The Impact of Chronic Pesticide Exposure on Neuropsychological Functioning

The Psychological Record - This study compared neuropsychological test performance of individuals (n = 18) with an occupational history of pesticide exposure to individuals (n = 35) with no such...     

The Relationship Between Cognitive Ability and Positive and Negative Priming in Identity and Spatial Priming Tasks

The authors examined whether stimulus activation and inhibition in the identity priming task are related to the temporal lobe, and whether these processes in the spatial priming task are related to the parietal lobe. Forty participants performed spatial and identity positive and negative priming tasks, the Vandenberg Mental Rotation task, and the Digit Span task. Both men and women showed significant positive and negative priming in the identity and spatial tasks with no gender difference. The magnitude of identity positive priming was predicted by the Digit Span task, and the magnitude of spatial positive priming was predicted by the mental rotation task. Only women showed a correlation between spatial ability and spatial negative priming. The results are partially consistent with the dorsal-ventral model of cognitive inhibition.     

Inhibitory processes in young and older adults in a picture-word task

Abstract

The present study examines changes in healthy young and healthy older adults in the ability to inhibit partially activated information in a picture/word interference paradigm. On each trial, subjects received a cue (i.e., the word PICTURE or WORD) indicating which of two stimuli the subject should attend to in an upcoming picture/word display. the display always contained a superimposed picture and word (e.g., a picture of a DEER with the word TEA printed on it). Following display offset, and depending upon the initial precue, either a test picture (e.g., KETTLE) or a test word (e.g., MOOSE) was presented. the subject's task was to determine as quickly and as accurately as possible whether the test stimulus was related to the cued dimension of the earlier picture/word display. the speed to reject an unrelated test item (e.g., picture of a KETTLE when the precue was PICTURE) that was related to the ignored dimension of the picture/word display (e.g., the word TEA in the picture/word display) was used as an index of the efficiency of the inhibitory system. the results indicated that older adults had more difficulty than younger adults inhibiting a to-be-ignored word when it was related to a picture test item, but did not have more difficulty inhibiting a to-be-ignored picture when it was related to a word test item. the results indicate that an age-related deficit in the control of interfering information is dependent upon the fluency of the processing routes.     

Lexical ambiguity and the timecourse of attentional allocation in word recognition

In two experiments the allocation of attention during the recognition of ambiguous and unambiguous words was investigated. In Experiment 1, separate groups performed either lexical decision, auditory probe detection, or their combination. In the combined condition probes occurred 90, 180, or 270 ms following the onset of the lexical-decision target. Lexical decisions and probe responses were fastest for ambiguous words, followed by unambiguous words and pseudowords, respectively, which indicated that processing ambiguous words was less attention demanding than unambiguous words or pseudowords. Attention demands decreased across the timecourse of word recognition for all stimulus types. In Experiment 2, one group performed the lexical-decision task alone, whereas another group performed the lexical-decision task during the retention interval of a short-term memory task. The results were consistent with those from Experiment 1 and showed that word recognition is an attention-demanding process and that the demands are inversely related to the number of meanings of the stimulus. These results are discussed with regard to the structure of the mental lexicon (i.e., single vs. multiple lexical entries) and the effect of such a structure on attentional mechanisms.     

The brachium of the inferior colliculus: The human auditory pathways: A quantitative study

Counts of nerve fibers in the brachium of the inferior colliculus in man from birth to 97 years (28 brains) revealed an average on the right of 168,311/mm² and an average of 168,593/mm² on the left. The total fiber population for each level studied averaged 350,562 for section A (immediately adjacent to the inferior colliculus), 452, 372 for section B (center of brachium), and 559,242 for section C (immediately adjacent to the medial geniculate body). These figures were averaged from brains whose ages ranged from 11 to 89 years. The area of the brachium, as well as its total fiber population, increased as the medial geniculate body was approached. This indicates that fibers were entering the brachium at various points along its course from the inferior colliculus to the medial geniculate body or were leaving in the reverse direction. A lower fiber density was found in infant brains, and a loss of nerve fibers was evident in the 91- and the 97-year-old specimens.     

Age and the allocation of attention across the time course of word recognition.

Younger and older adults performed lexical decisions on ambiguous words, unambiguous words, and pseudowords, and simultaneously responded to an auditory probe presented at stimulus onset asynchronies (SOAs) of 90, 180, or 270 ms. For both age groups, lexical decisions and probe responses were faster for ambiguous words than for unambiguous words, and slowest for pseudowords. For the older adults, but not the younger adults, lexical decisions were slower when the probe was presented (the dual-task condition), compared with a control condition in which the lexical decision was performed alone. The older participants also showed slower tone-detection responses in the dual-task condition than when the tone was presented alone. For all participants, proportional tone-detection times (compared with tones in isolation) decreased with increasing SOA, but this decrease was less pronounced in the older group. Finally, the time between responses in the dual-task condition was longer for older than for younger adults. The results indicate that word meaning influences the allocation of attention similarly for younger and older adults, but that older adults suffer a cost and become disproportionately slower in processes related to response coordination and output.     

Good-Enough Representations in Language Comprehension

People comprehend utterances rapidly and without conscious effort. Traditional theories assume that sentence processing is algorithmic and that meaning is derived compositionally. The language processor is believed to generate representations of the linguistic input that are complete, detailed, and accurate. However, recent findings challenge these assumptions. Investigations of the misinterpretation of both garden-path and passive sentences have yielded support for the idea that the meaning people obtain for a sentence is often not a reflection of its true content. Moreover, incorrect interpretations may persist even after syntactic reanalysis has taken place. Our good-enough approach to language comprehension holds that language processing is sometimes only partial and that semantic representations are often incomplete. Future work will elucidate the conditions under which sentence processing is simply good enough.     

Bulimic symptoms and body image dissatisfaction in college women: more affected by climate or race?

The authors examined bulimic symptoms and body image dissatisfaction (BID) in a sample of college women. No differences were found in comparisons of bulimic symptoms or BID between Southern and Northern White women, and both groups reported similar levels of awareness and internalization of sociocultural aesthetic standards of appearance. Southeastern Black women reported (a) significantly lower levels of bulimic symptoms in comparison with White women from the North and (b) lower levels of BID in comparison with White women from both Southern and Northern regions. Further, Southeastern Black women were significantly less likely to be aware of and endorse mainstream standards of appearance in comparison with both groups of White women. Findings support the hypothesis that having a positive body image and less susceptibility to mainstream aesthetic standards of appearance may reduce the risk of eating disorder pathology in Black women.     

Depth of processing and recall of threat material in fearful and nonfearful individuals

Although many studies have examined the nature of memory distortions in anxious individuals, few have considered biases in specific memory processes, such as encoding or retrieval. To investigate whether the presentation of threat material facilitates encoding biases, spider fearful (n=63), blood fearful (n=73), and nonfearful (n=75) participants encoded spider related, blood related, and neutral words as a function of three levels of processing (i.e., structural, semantic, and self referent). Participants subsequently completed either a free recall or a recognition task. All participants demonstrated a partial depth of processing effect, such that they recalled more words encoded in the self referent condition than in the other two conditions, but groups did not differ in their recall of stimuli as a function of word type. Relative to participants in the other groups, spider fearful participants had fewer spider related intrusions in the recall condition, and they made fewer errors in responding to structural and semantic encoding questions when spider related words were presented. These results contribute to an increasingly large body of literature suggesting that anxious individuals are not characterized by a memory bias toward threat, and they raise the possibility that individuals with spider fears process threat-relevant information differently than individuals with blood fears.