Effects of speaking rate and lexical status on phonetic perception

Among the contextual factors known to play a role in segmental perception are the rate at which the speech was produced and the lexical status of the item, that is, whether it is a meaningful word of the language. In a series of experiments on the word-initial /b/-/p/ voicing distinction, we investigated the conditions under which these factors operate during speech processing. The results indicated that under instructions of speeded responding, listeners could, on some trials, ignore some later occurring contextual information within the word that specified rate and lexical status. Importantly, however, they could not ignore speaking rate entirely. Although they could base their decision on only the early portion of the word, when doing so they treated the word as if it were physically short--that is to say, as if there were no later occurring information specifying a slower rate. This suggests that listeners always take account of rate when identifying the voicing value of a consonant, but precisely which information within the word is used to specify rate can vary with task demands.     

Associative effects of US preexposure: modulation of conditioned responding by an excitatory training context

In two experiments we examined factors that contribute to retarded emergence of conditioned responding to a conditioned stimulus (CS) trained in a context in which unsignaled unconditioned stimuli (USs) had previously been administered. In both experiments water-deprived rats were used in a conditioned lick suppression task to measure the conditioned response elicitation potential of the CS and the training context. From Experiment 1 we determined that nonreinforced exposure to the excitatory context after US preexposure and prior to CS-US pairings in that context eliminated the conditioned response deficit observed on a subsequent test of the CS. The recovery from the US preexposure deficit was nearly as great in animals that received nonreinforced exposure to the excitatory training context after the CS-US pairings but prior to the ultimate test of the CS. From Experiment 2 we determined that the recovery induced by contextual deflation after CS training was specific to deflation of the context in which the CS was trained as opposed to another excitatory context. In total, these experiments suggest that context-US associations partially mask the expression of a learned CS-US association. These results are discussed in terms of recent models of conditioned response generation.     

The comparator hypothesis of conditioned response generation: manifest conditioned excitation and inhibition as a function of relative excitatory strengths of CS and conditioning context at the time of testing

In the present research water-deprived rats were used in a conditioned lick suppression paradigm to test and further develop Rescorla's (1968) contingency theory, which posits that excitatory associations are formed when a conditioned stimulus (CS) signals an increase in unconditioned stimulus (US) likelihood and that inhibitory associations develop when the CS signals a decrease in US likelihood. In Experiment 1 we found that responding to a CS varied inversely with the associative status of the context in which the CS was trained and that this response was unaltered when testing occurred in a distinctively dissimilar context with a different conditioning history, provided associative summation with the test context was minimized. These results suggest that manifest excitatory and inhibitory conditioned responding is modulated by the associative value of the training context rather than that of the test context. In Experiment 2 it was demonstrated that postconditioning decreases in the associative value of the CS training context reduced the effective inhibitory value of the CS even when testing occurred outside of the training context. Moreover, this contextual deflation effect was specific to the CS training context as opposed to any other excitatory context. Collectively, these studies support the comparator hypothesis, which states that conditioned responding is determined by a comparison of the associative strengths of the CS and its training context that occurs at the time of testing rather than at the time of conditioning. This implies that all associations are excitatory and that responding indicative of conditioned inhibition reflects a CS-US association that is below (or near) the associative strength of its comparator stimulus. It is suggested that response rules which go beyond a monotonic relation between associative value and response strength can partially relieve learning theories of their explanatory burdens, thereby allowing for simpler models of acquisition.     

Computerphobia

Five studies of over 450 university students presented a comprehensive picture of computer-phobia. Three research and clinically based self-report instruments were developed to measure three nearly independent dimensions of computerphobia-computer anxiety, computer attitudes, and computer cognitions and feelings. Results indicated that older students were more computer anxious, but did not have more negative attitudes, cognitions, or feelings, than did younger students. Women had more negative attitudes than did men. Feminine-identity students showed more anxiety and negative attitudes than did masculine-identity students, regardless of gender. White students had more anxiety and more positive attitudes than did nonwhite students. Computerphobia was related to other anxiety measures (mathematics, state, and trait), but was a separate construct. Experience with computer interaction did not reduce anxiety or improve attitudes. Finally, regardless of academic major, computer-anxious students showed less computer aptitude, literacy, and interest. Implications for treating computerphobia are discussed.     

The Computerphobia Reduction Program: Year 1. Program development and preliminary results

The program development and first-year results of a 3-year U.S. Department of Education Fund for the Improvement of Postsecondary Education (FIPSE) grant are described. The identification of computerphobics and the types of discomfort they experience are defined. A clinically based 5-week model computerphobia reduction and skills-acquisition program is presented. Screening and assessment measures are outlined and three treatment modules—two individual treatments (systematic desensitization and thought stopping) and an information/support group—are described. The first-year results demonstrate significant pretreatment-to-posttreatment change in anxiety, attitudes, cognitions, and feelings. Plans are discussed for further evaluation and program expansion.     

Effect of speaking rate on the perceptual structure of a phonetic category

When listeners process temporal properties of speech that convey information about the phonetic segments of the language, they do so in a rate-dependent manner. This is seen as a shift in the location of the phonetic category boundary along a temporal continuum toward longer values of the acoustic property in question, as speech is slowed. In a series of experiments, we found that the adjustment for rate is not confined to the region of the category boundary, but extends throughout the phonetic category. Specifically, a change in rate modified the range of stimuli identified as members of a phonetic category, as well as which stimuli were overtly judged to be good exemplars of the category. These findings suggest that the listener's adjustment for speaking rate entails a comprehensive perceptual remapping between acoustic signal and phonetic structure.     

Adolescents' self-esteem measured as a specific score on the Strong-Campbell Interest Inventory

Scores on the "Your Characteristics" section of the Strong-Campbell Interest Inventory (SCII) of 178 high school students (80 boys, 98 girls) were analyzed to determine if what we know about adolescents' self-esteem will predict scores. These adolescents obtained means similar to those of average adults. Implications for counselors are noted.     

The role of performance-related similarity in social comparison of abilities: A test of the related attributes hypothesis

The hypothesis that individuals evaluate their abilities by comparison with others who are similar on nonability attributes that are related to performance has been supported in recent experiments. However, since these experiments did not include conditions in which attributes were unrelated to performance, they provide no evidence that it was the relationship of attributes to performance that explains why subjects compared with similar others. In the present experiment, 66 female undergraduates could choose to compare their test performance to the performance of women who were similar or dissimilar to themselves in physical attractiveness and the college they attended. In a 2 × 2 design these attributes were either related or unrelated to test performance. Results showed that only the performance relevance of college attended influenced comparison choices. Subjects compared with similarly attractive women even when attractiveness was unrelated to performance. These results indicate that identification of the conditions in which people do and do not consider the relevance of attributes to performance in selecting comparison others warrants attention.     

Identifying the speech codes

Models of speech processing typically assume that speech is represented by a succession of codes. In this paper we argue for the psychological validity of a prelexical (phonetic) code and for a postlexical (phonological) code. Whereas phonetic codes are computed directly from an analysis of input acoustic information, phonological codes are derived from information made available subsequent to the perception of higher order (word) units. The results of four experiments described here indicate that listeners can gain access to, or identify, entities at both of these levels. In these studies listeners were presented with sentences and were asked to respond when a particular word-initial target phoneme was detected (phoneme monitoring). In the first three experiments speed of lexical access was manipulated by varying the lexical status (word/nonword) or frequency (high/low) of a word in the critical sentences. Reaction times (RTs) to target phonemes were unaffected by these variables when the target phoneme was on the manipulated word. On the other hand, RTs were substantially affected when the target-bearing word was immediately after the manipulated word. These studies demonstrate that listeners can respond to the prelexical phonetic code. Experiment IV manipulated the transitional probability (high/low) of the target-bearing word and the comprehension test administered to subjects. The results suggest that listeners are more likely to respond to the postlexical phonological code when contextual constraints are present. The comprehension tests did not appear to affect the code to which listeners responded. A “Dual Code” hypothesis is presented to account for the reported findings. According to this hypothesis, listeners can respond to either the phonetic or the phonological code, and various factors (e.g., contextual constraints, memory load, clarity of the input speech signal) influence in predictable ways the code that will be responded to. The Dual Code hypothesis is also used to account for and integrate data gathered with other experimental tasks and to make predictions about the outcome of further studies.