Affect, Social Behavior, and the Brain in Williams Syndrome

ABSTRACT— Williams syndrome (WS) is a rare genetic disorder characterized by intellectual impairment and a distinctive physical and neuropsychological profile. Relative to their level of intellectual functioning, individuals with WS exhibit strengths in language and face recognition, with deficits in visual-spatial cognition. A heightened appetitive drive toward social interaction is a strong behavioral feature. Relative to other neurodevelopmental disorders, WS has a clearly defined genetic basis, together with a consistent neurocognitive profile of strengths and deficits. Thus, this disorder offers unique opportunities for elucidating gene–brain–behavior relationships. We focus on manifestations of the unusual social profile in WS, by examining data within and across levels of cognition, brain, and molecular genetics.     

Five Factor Biodata Inventory: resistance to faking

Faking on a biographical inventory compared to a traditional personality inventory was assessed in measuring the Five Factor Model of Personality. 705 subjects were randomly assigned to either an Answer Honestly or Faking condition. All subjects were recruited from psychology classes at two New Jersey State colleges. Women comprised 68.6% of the participants. The average age of the subjects was 24 yr. 383 subjects took part in the Answer Honestly condition. 322 participated in the Faking condition. In the Faking condition, subjects responded as if applying for the position of librarian. All subjects completed a biodata inventory, the NEO-Five Factor Inventory, a social desirability scale, a letter-cancellation task, and self-reported their grade point average. Criterion-related validity was assessed for both test scores across samples. Comparisons between samples indicated that subjects inflated scores on both inventories in socially desirable directions. Biodata Inventory scores were less elevated under the Faking conditions than the NEO-Five Factor Inventory scores.     

Evaluation of a Video Prompting and Fading Procedure for Teaching Dish Washing Skills to Adults with Developmental Disabilities

We evaluated a video prompting and fading procedure for teaching three adults with developmental disabilities to wash dishes. Video prompting involved showing video clips depicting each step of the task. All three adults reached 90–100% correct when video prompting was implemented. Following acquisition, video prompting was withdrawn, but performance deteriorated. Subsequently, a 3-step fading procedure was implemented in which the separate video clips were merged to form larger, multi-step segments of video. Performance reached 80–100% correct as the video prompts were re-applied and then faded. Performance decreased at the 3-month follow-up when prompting was removed, but stabilized at 80–90% correct when the third step in the fading sequence was reinstated. These data suggest a promising approach for fading video prompts.     

Promoting foot–leg movements in children with multiple disabilities through the use of support devices and technology for regulating contingent stimulation

The present study assessed the possibility of promoting pre-ambulatory foot–leg movements in children with multiple disabilities by motivating their action through contingent stimulation combined with a support device. Two children aged 10 and 8 years participated. Microswitch technology (i.e., pressure sensors under the shoes or optic sensors at the front–inner side of the shoes) served for detecting the foot–leg movements and providing contingent stimulation on their occurrence. Sensor activation produced 5 s of stimulation during intervention. Data showed that both children had significant increases in foot–leg movements during the intervention phases. Implications of the data in terms of skill acquisition and further intervention prospects are discussed.     

Abstract Conceptual Feature Ratings Predict Gaze Within Written Word Arrays: Evidence From a Visual Wor(l)d Paradigm

The Abstract Conceptual Feature (ACF) framework predicts that word meaning is represented within a high‐dimensional semantic space bounded by weighted contributions of perceptual, affective, and encyclopedic information. The ACF, like latent semantic analysis, is amenable to distance metrics between any two words. We applied predictions of the ACF framework to abstract words using eyetracking via an adaptation of the classical “visual word paradigm” (VWP). Healthy adults (n = 20) selected the lexical item most related to a probe word in a 4‐item written word array comprising the target and three distractors. The relation between the probe and each of the four words was determined using the semantic distance metrics derived from ACF ratings. Eye movement data indicated that the word that was most semantically related to the probe received more and longer fixations relative to distractors. Importantly, in sets where participants did not provide an overt behavioral response, the fixation rates were nonetheless significantly higher for targets than distractors, closely resembling trials where an expected response was given. Furthermore, ACF ratings which are based on individual words predicted eye fixation metrics of probe‐target similarity at least as well as latent semantic analysis ratings which are based on word co‐occurrence. The results provide further validation of Euclidean distance metrics derived from ACF ratings as a measure of one facet of the semantic relatedness of abstract words and suggest that they represent a reasonable approximation of the organization of abstract conceptual space. The data are also compatible with the broad notion that multiple sources of information (not restricted to sensorimotor and emotion information) shape the organization of abstract concepts. While the adapted “VWP” is potentially a more metacognitive task than the classical visual world paradigm, we argue that it offers potential utility for studying abstract word comprehension.     

Language development in children at risk for language impairment: cross-population comparisons

At 3 years of age the spontaneous language of 17 typically developing children was compared to two groups of toddlers who were at risk for language delay for very different reasons. One at-risk group, late talkers, appeared normal in all respects except for their delayed language. These 20 children scored at or below the fifteenth percentile for expressive vocabulary on the MacArthur Communicative Development Inventory (Fenson et al., 1993) when originally identified at 20-27 months of age and within the normal range on the Bayley Scales of Infant Development (Bayley, 1969). The other group, 21 children with unilateral focal brain injury, suffered localized damage to their brain prenatally, perinatally, or within the first 6 months of life. Results indicated that both of the at-risk groups were still significantly lower in vocabulary diversity and grammar at 3 years of age. There was also significantly greater variability in the at-risk groups than in the control groups, and in the children with focal brain injury than in the late talkers in both areas. The importance of language comprehension to development in this period was supported by two findings. First, children with focal brain injury had significantly lower scores than late talkers on the Index of Productive Syntax, a test of emerging grammar, and had been lower in comprehension on a standardized test of language comprehension a year earlier. Second, late talkers with delay in comprehension as well as production had significantly lower scores on IPSyn than those with normal comprehension, suggesting that they are at greater risk for continued delay. Qualitative analyses indicated that the at-risk groups produced the same kinds of errors, but that late talkers produced a substantially greater proportion of errors in obligatory contexts than did children with focal brain injury.     

Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluation of two cases

Technological aids such as microswitches may be critical to foster learning and development in children with multiple disabilities. In study I, a child with minimal motor behavior was provided with a microswitch for chin movements to assess whether he could learn to use these movements to activate environmental stimuli. In study II, a child with dystonic (difficult-to-control) behavior was provided with microswitches for two motor responses and two vocal utterances. We wanted to assess whether he could use both types of responses effectively (varying within each pair, consistent with choice performance). The results were highly encouraging with both children. In study I, there was a significant increase in the childs responding, suggesting learning and contingency awareness. In study II, there was a significant increase in responding as well as response variation that suggested choice behavior. The importance of microswitch devices in promoting new learning/developmental objectives and improving quality of life is discussed.     

Disruption of responding maintained by conditioned reinforcement: alterations in response-conditioned-reinforcer relations

An observing procedure was used to investigate the effects of alterations in response-conditioned-reinforcer relations on observing. Pigeons responded to produce schedule-correlated stimuli paired with the availability of food or extinction. The contingency between observing responses and conditioned reinforcement was altered in three experiments. In Experiment 1, after a contingency was established in baseline between the observing response and conditioned reinforcement, it was removed and the schedule-correlated stimuli were presented independently of responding according to a variable-time schedule. The variable-time schedule was constructed such that the rate of stimulus presentations was yoked from baseline. The removal of the observing contingency reliably reduced rates of observing. In Experiment 2, resetting delays to conditioned reinforcement were imposed between observing responses and the schedule-correlated stimuli they produced. Delay values of 0, 0.5, 1, 5, and 10 s were examined. Rates of observing varied inversely as a function of delay value. In Experiment 3, signaled and unsignaled resetting delays between observing responses and schedule-correlated stimuli were compared. Baseline rates of observing were decreased less by signaled delays than by unsignaled delays. Disruptions in response-conditioned-reinforcer relations produce similar behavioral effects to those found with primary reinforcement.     

Cognitive development following early brain injury: evidence for neural adaptation

Over the past few decades a large body of work from developmental neurobiology has shown that mammalian brain development is the product of dynamic and adaptive processes operating within highly constrained, but continually changing, biological and environmental contexts. The recent study of children with prenatal focal brain injury supports this dynamic view of development for humans. Children's injuries often affect substantial portions of one cerebral hemisphere, resulting in damage that would compromise cognitive ability in adults. However, longitudinal behavioral studies of this population have revealed only mild deficits. It is suggested here that children's capacity for adaptation reflects normal developmental processes operating against a backdrop of serious neural perturbation. Data from three behavioral domains--linguistics, spatial cognition and affective development--illustrate this complex profile of change.     

Words in the brain's language: an experimental investigation

According to Pulvermüller (1999), words are represented in the brain by cell assemblies (Hebb, 1949) distributed over different areas, depending on semantic properties of the word. For example, a word with strong visual associations will be represented by a cell assembly involving neurons in the visual cortex, while a word suggesting action will selectively activate neurons in the motor areas. The present work aims to test the latter hypothesis by means of behavioural measures. Specifically it tests the prediction that there should be a selective influence (in terms either of interference or priming) of performed/observed movements on the performance (reaction times and accuracy) of lexical decision involving words with a strong action association. Similarly, a selective influence of visual images on lexical decision involving words with strong visual associations should be observed. Two experiments were carried out. Results provided partial support for the hypothesis.