Cerebral hemispheric mechanisms in the retrieval of ambiguous word meanings

Targets related to ambiguous primes were projected to the left and right visual fields in a lexical priming experiment with stimulus onset asynchronies (SOA) of 35 and 750 msec. Right visual field results were similar to our earlier results with central projection (G. B. Simpson & C. Burgess, 1985, Journal of Experimental Psychology: Human Perception and Performance, 11, 28-39). Facilitation was found for the more frequent meaning at both SOAs and a decrease in facilitation for the less frequent meaning at the longer SOA. In contrast, left visual field results indicated a decay of facilitation for the more frequent meaning at the longer SOA, while activation for the subordinate meaning increased. Results suggest that, while automatic processing occurs in both hemispheres, only the left hemisphere engages in controlled processing of ambiguous word meanings. In addition, the present results support the idea that the right hemisphere has a special role in ambiguity resolution and that the right hemisphere lexicon possesses a richer endowment than earlier thought.     

Reaction to trauma: a cognitive processing model.

We integrated existing cognitive processing models of posttrauma reactions into a longitudinal model. Data were obtained after a multiple shooting in a city office block. The subject group comprised 158 office workers who were in the building at the time of the shootings. The methodology of this research was a repeated measures survey, with data collection at 4, 8, and 14 months posttrauma. Measures included the Impact of Events Scale (IES) and the Symptom Checklist-90-Revised. A path analysis was performed with the IES as an indication of cognitive processing. Intrusion and avoidance were shown to mediate between exposure to trauma and symptom development. Intrusion was also found to be negatively related to subsequent symptom levels. The findings provide provisional support for a cognitive processing model.     

Hypnosis, reporting bias, and suggested negative hallucinations.

We examined the role of reporting bias in hypnotic negative hallucinations by using a paradigm in which reporting bias was assessed independently of perceptual change. In Experiment 1, highly hypnotizable subjects reported significant loudness reductions when tested for hypnotic deafness. Later, however, these subjects biased their reported loudness reductions in the absence of perceptual change, and their reporting bias scores were almost as large as their hypnotic deafness reports. Subjects also biased their ratings of strategy use. In Experiment 2, ratings of blindness given in response to a hypnotic negative visual hallucination suggestion were significantly correlated with reporting bias scores obtained in this paradigm. Although hypnotic blindness and hypnotic deafness correlated significantly, the partial correlation between these variables was nonsignificant when reporting bias scores were statistically controlled. Theoretical implications are discussed.     

Histories of sexual abuse in adolescent male runaways

In this study, data on sexual victimization in the histories of 89 Canadian male runaways as well as information on physical victimization, family structure, family financial stability, delinquent and criminal activities, and reasons for running away from home were evaluated. The population of male runaways evidenced dramatically higher rates of sexual and physical abuse than did randomly sampled populations. Sexually abused and nonsexually abused male runaways shared characteristics noted in the literature as common to runaways: problem families, high rates of delinquency, depression, tension, low self-image, and history of physical abuse. Sexually abused male runaways differed from nonsexually abused runaways in their reactions to their runaway event, with sexually abused male runaways responding in highly avoidant patterns coupled with extreme withdrawal from all types of interpersonal relationships. These differences are explained as consistent with known sequelae of sexual abuse, and the implications for treatment by runaway shelters and for further research are suggested.     

Superimposition of response-independent reinforcement

Studies that have superimposed response-independent reinforcement (or reinforcers scheduled by contingencies placed on the absence of responding) upon conventional response-dependent schedules are reviewed. In general, providing alternative sources of reinforcement reduced response rates below the levels observed when alternative reinforcement was absent. However, response-rate elevation was sometimes found, particularly when rates of superimposed response-independent reinforcement were low. Superimposition of schedules providing reinforcers contingent on the absence of responding usually produced more severe response-rate decrements than superimposition of response-independent reinforcement. A variant of Herrnstein's equation, which assumes that some of the alternative reinforcers function as if they were delivered by baseline response-dependent source of reinforcement, is in qualitative agreement with the overall body of results obtained, and can predict both increases and decreases in response rate as resulting from superimposed reinforcers.     

Criminal profiling from crime scene analysis

Since the 1970s, investigative profilers at the FBI's Behavioral Science Unit (now part of the National Center for the Analysis of Violent Crime) have been assisting local, state, and federal agencies in narrowing investigations by providing criminal personality profiles. An attempt is now being made to describe this criminal-profile-generating process. A series of five overlapping stages lead to the sixth stage, or the goal of apprehension of the offender: (1) profiling inputs, (2) decision-process models, (3) crime assessment, (4) the criminal profile, (5) investigation, and (6) apprehension. Two key feedback filters in the process are: (a) achieving congruence with the evidence, with decision models, and with investigation recommendations, and (b) the addition of new evidence.     

Semantic and associative priming in the cerebral hemispheres: some words do, some words don't ... sometimes, some places

This study investigated spreading activation for words presented to the left and right hemispheres using an automatic semantic priming paradigm. Three types of semantic relations were used: similar-only (Deer-Pony), associated-only (Bee-Honey), and similar + associated (Doctor-Nurse). Priming of lexical decisions was symmetrical over visual fields for all semantic relations when prime words were centrally presented. However, when primes and targets were lateralized to the same visual field, similar-only priming was greater in the LVF than in the RVF, no priming was obtained for associated-only words, and priming was equivalent over visual fields for similar + associated words. Similar results were found using a naming task. These findings suggest that it is important to lateralize both prime and target information to assess hemisphere-specific spreading activation processes. Further, while spreading activation occurs in either hemisphere for the most highly related words (those related by category membership and association), our findings suggest that automatic access to semantic category relatedness occurs primarily in the right cerebral hemisphere. These results imply a unique role for the right hemisphere in the processing of word meanings. We relate our results to our previous proposal (Burgess & Simpson, 1988a; Chiarello, 1988c) that there is rapid selection of one meaning and suppression of other candidates in the left hemisphere, while activation spreads more diffusely in the right hemisphere. We also outline a new proposal that activation spreads in a different manner for associated words than for words related by semantic similarity.