Note on the “semantic” and the “absolute” concept of truth

Philosophical Studies -     

Regional cerebral blood flow patterns during verbal and nonverbal auditory activation

Current views of the relationship between audition and cerebral function suggest that increases in regional cerebral blood flow (rCBF) would occur in the superior, mid, and posterior portions of the temporal lobes, and that these changes would be more lateralized to the left hemisphere for a verbal than a nonverbal auditory task. We measured rCBF using the xenon inhalation technique in a group of healthy subjects during three conditions: (1) resting baseline, (2) auditory verbal activation (listening for word meaning), and (3) auditory nonverbal activation (listening for reduction of intensity in a series of noise bursts). Both verbal and nonverbal conditions produced highly significant increases in rCBF over the left posterior Sylvian region with a trend for verbal activation to evoke a wider area of flow increase than the nonverbal task.     

Conditions on rate normalization in speech perception

Recent work by Summerfield (1975) and others indicates that a listener’s phonemic judgments may vary with the utterance rate of prior context. In particular, if a phonemic distinction is signaled by a temporal cue such as voice onset time (VOT), faster utterance rates tend to shift the phoneme boundary toward smaller values of that cue. The listener thus appears to “normalize” temporal cues according to utterance rate. In the present experiment, subjects identified syllables varying in VOT ([ga]-[k^ha]) following either a slow or a fast version of the phrase “Teddy hears_ _ _ _ .” Typical normalization effects were observed when the precursor phrase and target syllable had formant frequencies corresponding to an adult male vocal tract. However, a reversal of the typical pattern (i.e., a shift in the perceived voicing boundary towardlarger values of VOT with an increased utterance rate) occurred when the precursor and target had formant frequencies corresponding to an adult female vocal tract. Both normalization and “reverse” normalization effects were reduced or eliminated under several conditions of source change between precursor and target. These conditions included a change in fundamental frequency, a change in implied vocal-tract size (as reflected in an upward or downward scaling of formant frequencies), or both.     

Analogic and abstraction strategies in synthetic grammar learning: A functionalist interpretation

Subjects learned artificial grammars under two conditions of acquisition: paired-associate learning and observation of exemplars. The former procedure was strongly associated with the establishment of a fairly concrete memorial space consisting of specific items and parts of items and the use of an analogic strategy for making decisions about novel stimuli. The observation procedure was strongly associated with the induction of an abstract representation of the rules of the grammar and the use of a correspondence strategy for decision making. Moreover, this latter procedure led to more robust knowledge and better overall performance. Analyses of both objective response patterns and subjective introspections yielded coordinated data in support of this distinction. The relationships between acquisition condition and cognitive strategy are discussed from a functionalist point of view.     

Organizational vs retrieval factors in the development of digit span

Three possible sources of memory span growth were tested with a modified version of the digit span task using subjects 6, 8, 11, and 19 years of age. There was no developmental trend in facilitation due to experimenter-imposed organization of the input strings, ruling out simple input-organizational theories. The notion that children are deficient at organizing retrieved information was also found to be untenable. The data support the view that older subjects use more selective retrieval strategies, strategies which are better suited to the encoded material. The largest improvement in retrieval selectivity occurred between sixth grade and college. Recency effects were smaller for the younger subjects than for older subjects, with first graders showing significantly less recency than third graders, sixth graders, and college students. Improved item identification during input may account for this finding.     

MEMORY AND COGNITIVE ABILITIES IN UNIVERSITY PROFESSORS:

Abstract— Professors from the University of California at Berkeley were administered a 90-min test battery of cognitive performance that included measures of reaction time, paired-associate learning, working memory, and prose recall. Age effects among the professors were observed on tests of reaction time, paired-associate memory, and some aspects of working memory. Age effects were not observed on measures of proactive interference and prose recall, though age-related declines are generally observed in standard groups of elderly individuals. The findings suggest that age-related decrements in certain cognitive functions may be mitigated in intelligent, cognitively active individuals     

SPLITTING THE BEAM:

Abstract— In an effort to examine the flexibility with which attention can be allocated in visual space, we investigated whether subjects could selectively attend to multiple noncontiguous locations in the visual field We examined this issue by perching two separate areas of the visual field and requiring subjects to decide whether the letters that appeared in these locations matched or mismatched while distracters that pinned either the match or mismatch response were presented between the cued locations. If the distracters had no effect on performance, it would provide evidence that subjects can divide attention over noncontiguous areas of space. Subjects were able to ignore the distracters when the targets and distracters were presented as nooses stimuli (i e, when premises were changed into the targets and distracters). In contrast, when the targets and distracters were presented as sudden-onset stimuli, subjects were unable to ignore the distracters. These results begin to define the conditions under which attention can be flexibly deployed to multiple noncontiguous locations in the visual field.