An Exploration of Right-Hemisphere Contributions to the Pragmatic Impairments of Autism

This study examined the potential contribution of the right hemisphere to the communicative impairments of autism. Pragmatic language measures sensitive to right-hemisphere damage were administered to nonretarded adults with autism and to controls matched on age and intellectual ability. The experimental battery included measures of humor, inference, and indirect request comprehension. Autistic subjects performed significantly less well than controls on all measures, replicating results of an earlier investigation by Rumsey and Hanahan (Journal of Clinical and Experimental Neuropsychology,12,81, 1990). The performance of the autistic group on the three tasks was also similar to that of right-hemisphere stroke patients reported previously (Molloy, Brownell, & Gardner, in Y. Joanette and H. M. Brownell (Eds.),Discourse ability and brain damage: Theoretical and empirical perspectives,New York: Springer-Verlag, 1990, pp. 113–130). Generalizability of these results and implications for the neuropathology of autism are discussed.     

Putting to a bigger hole: Golf performance relates to perceived size

When people are engaged in a skilled behavior, such as occurs in sports, their perceptions relate optical information to their performance. In the present research, we demonstrate the effects of performance on size perception in golfers. We found that golfers who played better judged the hole to be bigger than did golfers who did not play as well. In follow-up laboratory experiments, participants putted on a golf mat from a location near or far from the hole and then judged the size of the hole. Participants who putted from the near location perceived the hole to be bigger than did participants who putted from the far location. Our results demonstrate that perception is influenced by the perceiver’s current ability to act effectively in the environment.     

Understanding dynamic and static displays: using images to reason dynamically

We examined expert meteorologists as they created a weather forecast while working in a naturalistic environment. We examined the type of external representation they chose to examine (a static image, a sequence of static images, or a dynamic display) and the kind of information they extracted from those representations (static or dynamic). We found that even though weather is an extremely dynamic domain, expert meteorologists examined very few animations, examining primarily static images. However, meteorologists did extract large amounts of dynamic information from these static images, suggesting that they reasoned about the weather by mentally animating the static images rather than letting the software do it for them.     

Individual differences in working memory capacity and episodic retrieval: examining the dynamics of delayed and continuous distractor free recall

Two experiments explored the possibility that individual differences in working memory capacity (WMC) partially reflect differences in the size of the search set from which items are retrieved. High- and low-WMC individuals were tested in delayed (Experiment 1) and continuous distractor (Experiment 2) free recall with varying list lengths. Across both experiments low-WMC individuals recalled fewer items than high-WMC individuals, recalled more previous list intrusions than high-WMC individuals, and recalled at a slower rate than high-WMC individuals. It is argued that low-WMC individuals' episodic retrieval deficits are partially due to the fact that these individuals search through a larger set of items than high-WMC individuals. Simulations based on a random search model were consistent with these general conclusions.     

Executive function as a function of sub-clinical psychopathy

Some aspects of executive function are thought to be dysfunctional in psychopathic individuals. We administered a small battery of neuropsychological tests (spatial alternation task, object alternation task, and Porteus Maze) to two samples of college students and obtained a measure of psychopathy via a self-report questionnaire. Psychopathic traits were related to the tests of object alternation and Porteus Maze but not to the spatial alternation task. Our results support the hypothesis of orbitofrontal cortex (OFC) dysfunction with sparing of dorsolateral prefrontal cortex (DLPFC) in psychopathy and provide a downward extension of this theory to sub-clinical levels of psychopathy.     

Levels of processing effects on implicit and explicit memory tasks: using question position to investigate the lexical-processing hypothesis

One interpretation of levels of processing effects (LOP) on priming in implicit tests of memory is in terms of deficits in lexical processing during shallow study tasks. In two experiments the extent of lexical processing engaged in during standard shallow encoding tasks was manipulated by placing the encoding question either before or after the target stimulus. Clear evidence was found in explicit memory tasks that placing the question after the target stimulus increased the depth of processing of words presented in shallow encoding tasks. In contrast, there was no evidence of such an effect on the priming observed in implicit memory tasks. The results suggest that the role of lexical processing in LOP effects on priming requires further specification.