Brain, Behavior, and the Emergence of Cognitive Competence

A program-project grant supported by the National Institute of Child Health and Human Development (HD-38051)

Research Updates:

RESEARCH UPDATE - JANUARY 2006

Brain, Behavior, and Emergence of Cognitive Competence is a Program-Project (supported by NICHD grant HD38051) comprised of an administrative core and seven independent but interrelated research projects outlined below. This page provides an update on the progress of each project to date:

Comparative Studies of Category Learning by Humans and Nonhuman Primates (Smith)

The Emergence of Cognitive Competence (Rumbaugh)

The Emergence of Numerical Competence (Beran & Johnson-Pynn)

Comparative Studies of Primate Spatial Cognition and Memory (Menzel & Fragaszy)

The Evolution of Neuroanatomical Asymmetry and Spatial Transformation (Hopkins)

The Emergence of Cognitive Competence (Washburn & Espy)

Measuring Executive Attention in Infancy and Childhood (Rothbart & Posner)

Project Updates:

Comparative Studies of Category Learning by Humans and Nonhuman Primates (Smith)

1. We programmed procedures that instantiate the randomization technique of the General Recognition Theory, so that humans and animals can participate in one of the critical paradigms of the proposal. We ran humans and monkeys in this paradigm.
2. We programmed procedures that let us study humans' and animals' uncertainty monitoring in categorization tasks. We ran humans and monkeys in this paradigm.
3. We programmed Stroop-like procedures that will let us occupy humans' and monkeys' focal minds so we can study their implicit categorization processes selectively. We ran humans using these concurrent-task procedures.
4. We programmed the procedures that let us conduct dot-distortion category-learning studies with humans and nonhuman primates. We ran humans and monkeys with these procedures.
5. We programmed the procedures that will let us collect similarity-scaling data from humans and monkeys. We ran humans and monkeys in these procedures.
6. We constructed touch-screen procedures that let us study abstraction-based and exemplar-based processing in category learning. We ran humans and pigeons in these procedures.
7. We constructed procedures that let us study numerical categorization in nonhuman primates and study animals' uncertainty responding when they face difficult numerical discriminations. We ran monkeys in these procedures.
8. We constructed procedures that let us study monkeys' performance when they must work for blocks of trials without feedback. This is potentially an important innovation, because in this circumstance the monkey must develop its task strategy cognitively and decisionally for it will not be able use associative cues and reinforcement histories in doing so. We ran humans and monkeys in these procedures
9. We developed procedures that will let us study the processes of categorization by humans and animals in visual-search contexts. We ran humans in these procedures.
10. We developed additional procedures that will let us study the effect of specific-token familiarity on the recognition of category targets in visual-search tasks. We ran humans in these procedures.
11. We developed procedures to explore the capacity for uncertainty monitoring as it is expressed in Same-Different tasks that are deliberately made sophisticated using infinitely variable stimulus contexts. We ran humans in these procedures.
12. We developed procedures for giving multiple uncertainty-monitoring tasks simultaneously with interleaved trial types, to ask whether uncertainty responses are a general response that can extend across several task domains at once. We ran humans and monkeys on these procedures.

STUDIES AND RESULTS:

1. We completed a study showing that humans and monkeys categorize similarly in the randomization paradigm. We believe this is the first use of this paradigm with nonhuman primates.
2. We completed a study showing that humans and monkeys monitor uncertainty similarly in the randomization paradigm.
3. We completed studies showing that concurrent cognitive loads affect stimulus-based responses to middle stimuli qualitatively differently from uncertainty-based responses to stimuli that happen to lie in the middle of a stimulus continuum. This bears on a 100-year-old theoretical issue about whether uncertainty responses are higher level and metacognitive, or whether they are lower-level and stimulus bound.
4. We completed the first studies of dot-distortion categorization by nonhuman primates.
5. We completed a human similarity-scaling study using our new techniques. In the analogous monkey study, monkeys did not yet master the requirement for responding Same and Different in an infinitely variable stimulus space, and so we will have to plan additional training for them.
6. We completed a study showing that pigeons, like humans, pass through an early stage in category learning wherein they show abstraction-based categorization, and a later stage wherein they show exemplar-based categorization.
7. We completed a group of studies showing that monkeys monitor uncertainty adaptively in difficult numerical-categorization tasks. This was the first extension of uncertainty-monitoring research to the important domain of numerical cognition.
8. We completed a group of studies showing that humans and nonhuman primates can make adaptive uncertainty responses even when denied trial-by trial feedback. This forces one to interpret those uncertainty responses at a higher, cognitive level.
9. We completed a group of studies showing the profound impairment of the processes of categorization when these encounter visual complexity and the need for visual search.
10. We completed a group of studies showing the strong dependence of participants on exemplar processing and specific-token familiarity when the processes of categorization encounter visual complexity and the need for visual search.
11. We completed a group of studies exploring uncertainty monitoring by humans when they face Same-Different judgments in infinitely variable stimulus contexts. Our current results suggest that Same and Different are qualitatively distinct and separate judgments, and that humans do not feel or monitor, or cannot respond adaptively to, a region of uncertainty or difficulty between these two decisional states.
12. We completed a group of studies showing that humans can monitor uncertainty effectively even when trials of several distinct types are interleaved within ongoing task performance. In the analogous monkey study, the animals are still having great difficulty interleaving the several tasks, leaving us unable to answer as yet the uncertainty-monitoring question.

SIGNIFICANCE: This research represents several milestone accomplishments in the field of category learning. It extends to nonhuman primates several methods (dot-distortion technique, confidence ratings, unreinforced trial blocks, mathematical modeling) that are influential in the study of categorization by humans. It bridges between cognitive domains (e.g., concept learning, metacognition, numerical cognition, visual search) and opens the door for new issues (e.g., brain mechanisms, evolutionary divergence and convergence).

The Emergence of Cognitive Competence (Rumbaugh)

STUDIES AND RESULTS:
1. Chimpanzee Lexigram Acquisition Paradigm. A great deal of deliberation and group discussion between Rumbaugh, King, Beran, Menzel, & Washburn has characterized this effort. The first decision was that we begin with rather subtle manipulations of stimulus salience. Twelve pairs of clip-art stimuli were selected randomly and assigned to various treatment conditions in which one member (A) of each pair was to receive special emphasis (e.g., salience) and where that member was then presented before, after, or contiguously with its paired member (B). The computerized program initiated each new trial with a start key positioned in the center of the screen. When the subject moved the cursor into contact with that start key, the members of each pair were presented according to one of three conditions: Condition 1, in which salient stimulus A preceded nonsalient stimulus B; Condition 2 in which A was paired concurrently with B; and Condition 3 in which nonsalient stimulus B was presented prior to salient stimulus A.

Each pair of stimuli was presented 10 times during the session. Salience was enhanced for stimuli by four methods -- fading it in, slowly uncovering its image, having it wiggle on the screen, or having a flashing background. After both stimuli were removed at the end of their presentation from the computer screen, a red dot appeared in the same location, randomly selected, on the screen as one of the two images. The subject had only 1000 ms to contact that circle in order to receive a food pellet. This ensured attention to the stimuli when and wherever trials were presented. After all associative-pairing trials were completed, the stimuli were presented in MTS (i.e., matching to sample) test trials. All choices of the stimulus member that had been paired with a given sample were rewarded. None of the chimpanzees performed above chance levels during the matching-to-sample phase of the experiment. On 36 test trials, Lana was correct on 8 trials, Mercury was correct on 8 trials, and Panzee was correct on 6 trials (chance was 25%).

2. Macaque Stimulus Equivalence for Icons Representing Computerized Tasks. Rhesus monkeys in the lab have now learned to use not just one but two separate sets of icons to select among five tasks, where each task is presented for but five trials and where chosen tasks are not replaced once chosen. Interestingly, the tasks are selected in order of their descending preference in the generic program called SELECT. Each set of icons contains five symbols, then, where each represents one of five tasks. Selection of a specific icon brings up a specific task. We hold that these icons may have acquired some representational meaning for individual tasks. Any association between the two sets of icons has never been explicitly trained and certainly has not been subjected to any form of traditional reinforcement. Accordingly, the monkeys now give us the opportunity to determine whether, in accordance with their functional equivalence, the icons from different sets and never before seen together, have become associated. Their associations, if extant, will be assessed in an MTS protocol.

SIGNIFICANCE: As theorized by Rumbaugh and Washburn (2003), "reinforcers" are effective due to their salience. Accordingly, by emphasizing the salience of stimuli via special treatment (as with the chimpanzee work above) or through sharing common functional effectiveness, stimuli might well become associated - that is, learned. These two options do not, of course, exhaust means of enhancing the salience of stimuli. The chimpanzee work, summarized above, shows that not all efforts at stimulus enhancement necessarily work. The program summarized with them will be pursued but with more radical manipulations to enhance stimulus salience. We anticipate that we will better understand the learning of words through this research.

The Emergence of Numerical Competence (Beran & Johnson-Pynn)

STUDIES AND RESULTS:

1. Nonverbal Estimation During Numerousness Judgments by Adult Humans. We presented adult humans with a task in which they selected the larger of two sets of items created through the one-by-one addition of items on a computer screen. Participants repeated the alphabet out loud during trials so that they could not count the sets. This manipulation disrupted counting without affecting other cognitive capacities such as memory or attention, and performance of this experimental group was poorer compared to participants who counted the items. Reports of the number of items in a single set showed scalar variability as accuracy decreased and variability in responses increased with increases in true set size.
In addition, this computerized task was adapted for use with chimpanzees and rhesus monkeys. Two rhesus monkeys have completed a series of experiments in which the rate of item presentation, the amount of items presented, and the duration of set presentation were systematically varied to determine whether numerosity was controlling responding in this task. These monkeys performed above chance levels in selecting the larger set, and they did so across conditions, indicating that they were not responding to non-numerical stimulus dimensions such as amount or rate. In addition, performance was heavily dependent on the ratio of the smaller set to larger set across a range of 1 to 10 items, providing further support for an analogue magnitude form of representation in rhesus monkeys.

2. Estimation Mediates Preschoolers' and Chimpanzees' Numerical Reasoning. We tested the hypothesis that children (ages 3-5 years) and chimpanzees (Pan troglodytes) represent numerical quantities in an approximate rather than exact manner and that such representation is not limited by the number of items presented to them. Twenty preschoolers and 3 chimpanzees performed a magnitude comparison task requiring judgments between a variety of two-set scenarios, with sets differing by ratio, interval distance, and absolute set size. Children completed verbal-based tasks probing the relationship between counting proficiency and performance on the magnitude comparison task. Both species' performance improved significantly when ratios between comparison sets were small rather than large and was not significantly impacted by interval distance or absolute set size. Performance in counting proficiency tasks was not correlated with children's performance in the magnitude comparison task, suggesting that formal counting is dissociated from estimation.

3. Children's Addition. To date, we have collected data with 17 children ages 4 ½ to 6 years in which children respond to additions of items to these sets. Preliminary analyses revealed that ratio affected success, while condition (i.e., the quantities with respect to the order in which sets were deposited into the cups) did not.

4. Uncertainty Monitoring During Numerosity Judgments by Rhesus Monkeys (with Smith and Washburn). In a collaborative effort with two other PIs on this program project, we investigated the role that uncertainty plays in the numerousness judgments of monkeys. Two rhesus macaques assessed the number of dots in an array presented on a computer screen. Each trial involved the presentation of a set having more or fewer dots than a center value that was never presented in trials but was learned through response outcomes. After learning a center value, monkeys also were given an uncertainty response that let them decline to make a numerosity judgment on any trials they chose. Across center values that shifted across sessions, errors occurred most often for sets adjacent in numerosity to the center value. The monkeys also used the uncertainty response most frequently on these difficult trials. To demonstrate that these judgments were not made simply on the basis of the continuous variable of surface-area illumination, we conducted a second experiment that dissociated numerosity and surface area illumination, and monkeys' responded on the basis of numerosity both in making the primary more-than/less-than judgment and in their pattern of uncertainty responding. This research shows for the first time that animals' uncertainty-monitoring capacity extends to the domain of numerical cognition.
SIGNIFICANCE: We have shown that young children, chimpanzees, and rhesus monkeys can select the largest of multiple sets of items when those items are presented in a one-by-one manner into opaque containers, and the numerical representation during these tasks takes the form of analogue magnitudes. Performance is not limited by the absolute number of items presented, but it is dependent on the ratio of sets to each other. We have demonstrated that rhesus macaques respond to numerosity in tasks in which sets are presented sequentially. Duration, rate of presentation, and the amount of items presented do not interfere with the numerical judgments made in these tasks
We have demonstrated that adult humans who are prevented from using formal counting procedures perform similarly to the nonhuman primates. They estimate set sizes in such a manner as reflects analogue magnitude estimation, and performance is highly dependent on the ratio between sets, suggesting a shared mechanism for estimation of quantity across humans and nonhuman primates.

Comparative Studies of Primate Spatial Cognition and Memory (Menzel & Fragaszy)

STUDIES AND RESULTS

1a. Mazes: Software programming. Software originally written for the presentation of maze tasks in a joystick format was reprogrammed to permit the presentation of mazes and other spatial tasks to nonhuman primates in a touch-screen format. This reprogramming will permit the testing of capuchins in both touch-screen and joystick- versions of maze and detour tasks.
1b. Mazes: Testing capuchins in joystick format. We previously showed that monkeys and apes show nascent planning abilities while solving two-dimensional alley mazes using a joystick. To characterize asymptotic performance in joystick-controlled maze tasks, and to identify experiential factors that improve planning abilities (Experiment 3B), we are testing capuchins repeatedly with the set of 192 mazes in an ordered sequence. Two capuchins have completed 3 sets of replications. These two capuchins have shown a reduction in the number of incorrect alley entries per trial.

1c. Mazes: Testing capuchins in touch-screen format. We began training two different capuchin monkeys at the University of Georgia to solve spatial tasks in a touch-screen format. In the initial training task, a cursor appears in the middle of the video screen, and a target is visible in 1 of 8 directions on the screen. The subject's task is to contact the cursor manually and to drag the cursor into contact with the visible target by sliding the hand across the surface of the video screen. The capuchins are in an early stage of training but both appear to be capable of dragging a cursor across a video screen as required for this task.

2. Development of improved pointing devices. A modified joystick was designed and constructed for use with capuchin monkeys. In principle, the joystick will provide capuchins with an opportunity to use a laser pointer to pinpoint objects that are located outside their cage and out of reach.

3. Memory in outdoor tasks. We previously showed that a female symbol-competent chimpanzee could use a color video representation of an outdoor area as a guide to locating objects in that area. We conducted an experiment that demonstrates that the chimpanzee can use an impoverished, black-and-white video representation as a guide to locating objects in the outdoor area, after delays exceeding 10 minutes and probably as long as 16 hours. Additional trials with overnight (15+ h) delays are being conducted.

4. Comprehension of televised spatial information. Katherine Leighty completed a Ph.D. dissertation "Cross-dimensional object recognition in chimpanzees (Pan troglodytes)." In order to clarify the abilities of nonhuman primates to equate 3D objects with their 2D images Leighty presented 9 tasks to 4 adult chimpanzees at the Language Research Center. These tasks were scaffolded to provide insight into the complexity of the representation that is formed from a 2D depiction of a 3D object. In all tests, the experimenter concealed a food reward (marshmallow) beneath or within a target object. This hiding event was only visible to the subject on a 2D television screen via a live video feed. After viewing the hiding event, the subject was presented with the 3D object and distracter and allowed to search for the food reward. The first search choice for the food reward was recorded. The results demonstrated that chimpanzees were able to form complex object representations from their 2D depictions without the use of distinguishing local features. This suggests that chimpanzees have the capacity to represent objects from their 2D images using global form, thus securing the internal validity of results from previous cross-dimensional research.

5. Movement of objects in near space: producing spatial relations between objects. This project investigates the flexible use of allocentric frames of reference by monkeys and apes to arrange objects in space. The general paradigm involves giving the subject a stick in its home area and a tray in which to place the stick so that it can be returned to the Experimenter by sliding the tray outward underneath a frame piece. In the experimental conditions, the tray can slide out with the stick only when the stick is correctly positioned and inserted into a groove in the tray. Per trial, subjects are allowed to work with the stick until they succeed at returning it or give up. Trials are filmed. Conditions: A: (baseline): No alignment required. B: Linear alignment. We use four positions in the tray with respect to the frame of the cage: perpendicular, parallel, and offset 45 degrees to Left and to Right). C: Asymmetric linear alignment. One end of stick has a distinctive symmetrical knob and the groove in the tray has one matching depression to hold the knob. This condition uses the four positions used in (B) together with two positions for the knob (at each end of the stick). Thus, this task includes 8 positions. D: Linear alignment with a directional asymmetric feature. This task includes the same 8 positions as (C). The stick will have an asymmetrical knob at one end of the shaft. Tasks are presented in order of increasing difficulty, from A to D, until each subject has solved each task 10 times.
We filmed 10 successful trials per condition for 3 of the 4 chimpanzees. A fourth chimpanzee is currently working on level D. All four chimpanzees made a variety of positioning errors in Levels C and D, and these errors are expected to be informative in making comparisons with capuchins. We are currently working to classify the errors and to score the videotapes of the chimpanzees. Preparations are underway for the testing of capuchin subjects. A sliding tray and a smaller version of the form board and sticks are being constructed.

The Evolution of Neuroanatomical Asymmetry and Spatial Transformation (Hopkins)

STUDIES AND RESULTS:

Left vs. Right Hand Discrimination Study. To date, training on left-right discrimination has begun in 5 subjects. Training sessions consisted of 60 trials per session. Subjects were presented with a target (PVC tube with red end) and asked to touch the tube. Subjects were assigned a target hand (counterbalanced across subjects) and were rewarded when they touched the target with the target hand. The experimenter would say the corresponding target hand each time the target was presented (e.g. if the target hand was the right hand, the experimenter would present the target and say "right"). Presentation of the target began on the side of the body that corresponded to the target hand. When subjects scored 80% correct or better on 3 consecutive blocks of 20 trials (1 session) with this presentation, the presentation was moved to the center of the body. When subjects scored 80% or better on 3 consecutive blocks of this presentation, presentation was moved to the opposite side of the subject's body as the target hand. When criterion was met with this presentation, training began with the other hand. Subjects had difficulty when presentation training started with the opposite hand; therefore, a second procedure was implemented.
For this testing, training sessions consisted of 100 trials per session. Subjects were presented with one of two PVC tubes (one long red tube and one short blue tube with a piece of connector PVC on the end). Subjects were assigned a target hand (counterbalanced across subjects) and a target tube (counterbalanced across subjects) and were rewarded when they touched the target tube with the target hand. The experimenter would say the corresponding target color each time the target was presented (e.g. if the target color was red, the experimenter would present the target and say "red"). Trials were recorded each time the subject touched the target. A new trial touch was recorded only when the subject completely removed their hand from the target, brought the hand back inside the cage, and touched the target again. Subjects received a reward only when they touched the target with the target hand. Rewards were given in the form of clicker training as well as food rewards (banana/apple and juice). Trials were recorded when the subject touched the tube with only one hand. In the case that the subject touched the tube with both hands, the experimenter would wait until the subject removed both hands and touched the tube with only one hand.
Presentation of the target began on the side of the body that corresponded to the target hand. When subjects scored 90% or better on a session with this presentation, the presentation was moved to the center of the body. When subjects scored 90% or better on a session of this presentation, presentation was moved to the opposite side of the subject's body as the target hand. When criterion was met with this presentation, training began with the other hand using the other target tube. The process of presentation was repeated with this hand.
All subjects successfully completed training with one hand at the same side and center presentation stations but showed significant difficulty when the presentation station was on the opposite side of their body (e.g. when they were being trained to touch with their left hand but the target was presented on the right side of their body). When the target was presented on the opposite side of the body from the target hand, subjects failed to meet criterion after multiple sessions (progress as of 06/05/05).

Imitation Progress Report. Seven subjects are being trained to imitate a simple motor action (raising an arm above the head). The experimenter raises her right hand above her head and requests the subject to imitate. The target arm required for imitation is counterbalanced across subjects. Each trial in a training session begins when a subject is sitting in front of the cage with both hands down, not touching the mesh on the cage. The experimenter then raises her right hand above her head and tells the subject to imitate. The subject is rewarded when he/she correctly imitates the action with the target hand. Rewards consist of juice and small pieces of fruit. Training sessions last approximately 10 minutes per subject. Subjects currently being trained to imitate this action are 7 individuals (2 males and 5 females). To date, all subjects reliably raise the target hand to at least eye level. The next phase of training requires teaching the subject to raise their hand above their head without touching the mesh on the cage.

SIGNIFICANCE: The data thus far collected show that chimpanzee appear to be able to acquire the basic skills associated with discriminating left from right but do not show immediate generalization of the concepts of left and right. This might reflect an inherent lack of left-right discrimination ability or limitations in the training protocols.

The Emergence of Cognitive Competence (Washburn & Espy)

STUDIES AND RESULTS: Research directed toward specific aims were conducted in parallel with children at the Developmental Cognitive Neuroscience (DCN) Lab at Southern Illinois University, with adults in the Individual Differences in Executive Attention (IDEA) Laboratory at Georgia State University, and with monkeys and apes at the Language Research Center (LRC) of Georgia State University.

Study 1 (determinants of attention): Study 1 involves testing of children with tasks originally developed for the monkeys, and testing of monkeys with tasks originally developed for the preschool children. This year saw several important accomplishments in support of this study. First, tasks for the children were refined and pilot-tested at the DCN Lab. Included in this battery of tasks is a Stroop-like test that is being administered to the rhesus monkeys at the LRC. Second, child-friendly versions of several tasks (e.g., the inhibition task of Exp. 1.5) developed for the monkeys have been produced. Pending successful validation with the nonhuman primates, these will be added to the battery for the children. For each such task, within-subject manipulations of the cues for attention are being made so as to examine the relative potency of environmental, experiential, and executive constraints on attention. Third, a database of > 500 potential preschool participants at the DCN has been established this year, providing critical access to the children required for the proposed research. Although this activity was time-consuming and not directly linked to an experimental outcome, the success of this recruitment procedure will yield great results in subsequent years of research.

Experiment 2.1 (Set-switching): Two studies were conducted with the monkey at the LRC on set-switching. In the first, a card-sort task was developed and administered to the monkeys. This testing revealed the potency of the color cue and replicated the susceptibility to perseverations that we continue to find for macaques in other tasks. Preliminary results for this ongoing study were reported at the annual meeting of the Southeastern Psychological Association. In the second study, the numerical Stroop tasks was used to examine switching between response cues (number of stimuli or identity of the stimuli). This results of this study, which mirror published results for human adults with low working-memory span, was submitted for presentation at the annual meeting of the Psychonomic Society. Three extra-dimensional switching tasks that vary in response format have been developed in the DCN laboratory that will provide important bases for comparison with the LRC monkeys.

Experiment 2.3 (Monitoring): In collaboration with Smith and Beran, we have continued to examine the executive function of monitoring in a variety of tasks. In addition to the studies described in their project reports, we submitted for publication the results of two experiments designed to determine whether monkeys would use the "uncertain response" from Trial-1 on tasks that produced uncertainty (learning-set and mirror-image matching). The results demonstrated convincingly that monkeys know when they don't know.

Experiment 2.6 (Learning): We continued to study the "meaningful failures" of monkeys to learn relationally. Included in this effort this year were (a) a re-analysis of visuospatial memory performance, looking for a strategy-based explanation for monkeys' perseverations (results presented at the Southeastern Psychological Association meeting); (b) computer modeling using granular neural networks of the monkeys' failure to discriminate mirror-image stimuli (results presented at the American Psychological Society meeting), and (c) an extensive series of studies on the monkeys' failure to perform relational matching (presented at the meeting of the Southern Society for Philosophy and Psychology).

Experiment 2.7 (Numerical symbols): Graduate-student Gulledge completed his dissertation on the cognitive and cortical processes that support numerical judgments by monkeys and human adults. Graduate-student Harris also completed her Master's thesis on numerical cognition, part of a series of studies she has conducted on "What do the numeric symbols mean to monkeys?"

Study 3 (Improving executive attention): We continue to collect data from the animals on attention-task perforamance for subsequent analysis of practice and training effects. However, the pharmacological studies and the transcranial magnetic stimulation studies described in the proposal were not funded in the present cycle.

SIGNIFICANCE: These studies continue to illuminate the nature of attention and its relation to other cognitive constructs (learning, memory, executive function, language). Additionally, the data have implications for understanding and treating the cognitive disorders (such as attention deficits) that plague many children and adults.

Measuring Executive Attention in Infancy and Childhood (Rothbart & Posner)

STUDIES AND RESULTS: We have set up a laboratory for the for recording infant eye movements in three tasks. We have recruited an excellent postdoc and a number of research assistants. Our preliminary work with four year olds suggested that we might be better off with slightly more mature infants. We have so far run 33 infants, most are six months of age. The first twelve were used as pilots to set up our tasks so we have about 21 infants. Originally this was all we planned to run only 24, but new findings (see below) now make us wish to run 40 infants. We have so far analyzed the data from 9 of the infants in the three tasks and our preliminary results refer to them.

The three tasks we are studing are ambiguous spatial sequence, presentation with toys and presentation with masks. The first task is designed to help us measure effortful control by looking at anticipatory eye movements to unambiguous or ambiguous visual objects. The second is to allow examination of a situation in which there is substantial positive affect and the third where possible negative affect will occur. The 21 infants who will be part of our final sample were run without any special problems. We have used the Noldus Behavioral Recording system to code the data. The coding appears to be reliable and is going smoothly.

The preliminary data for this ongoing study are too few at present to base any final conclusions. However, we note that we are getting substantial correlations between self-regulation in the IBQ and positive and negative affect in the same measure. Positive affect is negatively correlated with negative affect at .45, while effortful control is positively related to positive affect (from IBQ) at .39 and negatively related to negative affect at -.38. Even though our infants are all about 6 months of age we find the variation in age to be negatively correlated with reaction time. This is to be expected. More surprising is the strong positive correlation between reaction times and negative affect (long RT with high negative affect). There are anticipatory looks but so far these are not sufficient to allow any firm conclusions. The data collected so far suggest that we are getting the various relationships that we hoped for among the measures taken at six months. When we finish coding all of the data, which we hope to do by the end of the summer, we will be in a stronger position to know how well it is all going.

SIGNIFICANCE: The significance of these findings have been enhanced by analyses of data we had previously collected. Our results have revealed a significant gene by attention interaction among six year olds that we have genotyped for dopamine genes and trained using our attention training methods. We studied two administrations of the ANT. We found prior to any training that children with the hetero long/short form of the dopamine transporter gene performed significantly more poorly in the ability to resolve conflict than those with the pure long form. There were not a sufficient number with the pure short form to analyze. The long/short form children also showed significantly poorer effortful control and EEG signs of conflict resolution. These effects were reduced following experience. Thus, we believe we have shown both important effects of attention training and an ability to predict from genotyping the children that might need this training. These finding make our effort to trace the temperament and attention differences to infancy and early childhood even more important.