Latency of different verbal responses to the same stimulus

A response of reading (letter O) or of naming (circle) can be given to the same sign O. The verbal reaction time is higher when naming than when reading (difference 100 millisec.). This fact verifies that naming is a longer process than reading, the difficulty of perceiving the stimulus being equal.

The response “zero” which may be given to the same sign is nearer to the reading-response time than the naming-response. These facts can be explained if we say that uncertainty for coding concrete signs is greater than for alphabetical or numerical signs.     

Vowel and consonant judgments are not independent when cued by the same information

Despite many attempts to define the major unit of speech perception, none has been generally accepted. In a unique study, Mermelstein (1978) claimed that consonants and vowels are the appropriate units because a single piece of information (duration, in this case) can be used for one distinction without affecting the other. In a replication, this apparent independence was found, instead, to reflect a lack of statistical power: The vowel and consonant judgments did interact. In another experiment, interdependence of two phonetic judgments was found in responses based on the fricative noise and the vocalic formants of a fricative-vowel syllable. These results show that each judgment made on speech signals must take into account other judgments that compete for information in the same signal. An account is proposed that takes segments as the primary units, with syllables imposing constraints on the shape they may take.     

Dissociating prelexical and postlexical processing of affective information in the two hemispheres: effects of the stimulus presentation format

Using a lexical decision task, the authors investigated whether brain asymmetries in the detection of emotionally negative semantic associations arise only at a perceptually discriminative stage at which lexical analysis is accurate or can already be found at crude and incomplete levels of perceptual representation at which word-nonword discrimination is based solely on guessing. Emotionally negative and neutral items were presented near perceptual threshold in the left and right visual hemifields. Word-nonword discrimination performance as well as the bias to classify a stimulus as a "word" (whether or not it actually is a word) were assessed for a normal, horizontal stimulus presentation format (Experiment 1) and for an unusual, vertical presentation format (Experiment 2). Results show that while the two hemispheres are equally able to detect affective semantic associations at a prelexical processing stage (both experiments), the right hemisphere is superior at a postlexical, perceptually discriminative stage (Experiment 2). Moreover, the findings suggest that only an unusual, nonoverlearned stimulus presentation format allows adequate assessment of the right hemisphere's lexical-semantic skills.     

Pigeons learn stimulus identity and stimulus relations when both serve as redundant,relevant cues during same-different discrimination training

The authors taught pigeons to discriminate displays of 16 identical items from displays of 16 nonidentical items. Unlike most same-different discrimination studies--where only stimulus relations could serve a discriminative function--both the identity of the items and the relations among the items were discriminative features of the displays. The pigeons learned about both stimulus identity and stimulus relations when these 2 sources of information served as redundant, relevant cues. In tests of associative competition, identity cues exerted greater stimulus control than relational cues. These results suggest that the pigeon can respond to both specific stimuli and general relations in the environment.     

Differential access to information and anticipated group interaction: impact on individual reasoning

Two studies examined the impact of relative differences in access to information and anticipated group interaction on individual reasoning. On 2 different reasoning tasks (P. C. Wason's [1966] selection task and D. Kahneman & A. Tversky's [1973] lawyer-engineer problem), participants sensing that they knew more in anticipation of group interaction or knew less when not anticipating interaction were less susceptible to typical cognitive biases demonstrated by these tasks. Study 2 also showed that the effect of these social contexts was contingent on the task presentation format. Thus, knowing more in anticipation of group interaction and knowing less when not anticipating group interaction seemingly compensated for task features that enhance suboptimal reasoning strategies. These results illustrate the importance of the social context in which reasoning is situated and are discussed in terms of cognitive tuning, social comparison, and social motivations.     

On the relationship between vowel and consonant identification when cued by the same acoustic information

When listening to speech, do we recognize syllables or phonemes? Information concerning the organization of the decisions involved in identifying a syllable may be elicited by allowing separate phonetic decisions regarding the vowel and consonant constituents to be controlled by the same acoustic information and by looking for evidence of interaction between these decisions. The duration and first formant frequency of the steady-state vocalic segment in synthesized consonant-vowel-consonant syllables were varied to result in responses of /bεd/, /bæd/, /bεt/, and /bæt/. The fact that the duration of the steady-state segment controls both decisions implies that that segment must be included in its entirety in the signal intervals on which the two decisions are based. For most subjects, no further significant interaction between the vocalic and consonantal decision is found beyond the fact that they are both affected by changes in the duration parameter. A model of two separate and independent phonetic decisions based on overlapping ranges of the signal adequately accounts for these data, and no explicit syllable level recognition needs to be introduced.     

Implicit access to semantic information

Three experiments investigating the patient M.S.'s semantic memory are reported. Experiments 1 and 2 involved a category-membership decision task, in which M.S. was asked to determine whether a noun was a member of a specified semantic category. His performance in Experiment 1 was impaired for nouns from living categories in comparison with nouns from nonliving categories, and this impairment was especially marked for nouns of low typicality. Experiment 2 demonstrated an equivalent pattern of very poor performance to nouns of low familiarity from living categories. In Experiment 3 the effect of a category label on lexical decision was examined, using category labels as primes preceding nouns or pronounceable nonwords. Facilitation from related category label primes was found for typical and untypical members of living and nonliving semantic categories. These findings demonstrate that M.S. has impaired knowledge of the structure of living semantic categories when explicit access to this information is required (Experiments 1 and 2), but that some form of preserved category structure can be demonstrated in tasks which assess this implicitly (Experiment 3).     

Access to perceptual and conceptual information in the left and right hemispheres.

It is assumed that there are hemispheric differences in the type of information available for the processing of word meanings, e.g., categorical or associative information. In the present experiment, we used a semantic priming paradigm to examine whether perceptual or conceptual properties of word meanings would be associated with the left or right hemisphere. The present experiment also examined time-course activation of these properties across the hemispheres, using short and long stimulus onset asynchronies. The results indicated that perceptual information is available only in the right hemisphere at an early rather than a late stage of target processing, while conceptual information is available in both hemispheres at both early and later stages of target processing. It is suggested that the imagery system in the right hemisphere may contribute to the perceptual priming observed in this hemisphere.     

Interhemispheric transfer of lever pressing as stimulus generalization of the effects of spreading depression

Rats trained to lever-press with spreading depression in one cerebral hemisphere showed weak responding when tested with depression shifted to the trained hemisphere. The rats were then divided into two groups: one group (normal) was permitted a single reinforced response with neither hemisphere depressed, the other group (depressed) was permitted a single reinforced response with the trained hemisphere depressed; both groups were then tested with the trained hemisphere depressed. Responding during this second test increased for both groups, but the magnitude of the increase tended to be greater for the depressed than for the normal group. Since memory transfer could not have occurred with the trained hemisphere depressed, the results were taken to indicate that the single reinforced response strengthened stimulus generalization between train-test conditions.     

A harbor seal can transfer the same/different concept to new stimulus dimensions

We investigated the formation of an abstract concept of same/different in a harbor seal by means of a two-item same/different task. Stimuli were presented on a TFT monitor. The subject was trained to respond according to whether two horizontally aligned white shapes presented on a black background were the same, or different from each other, by giving a no-go or go response. Training comprised of four stages. First, the same/different task was trained with two shapes forming two same problems (A–A and B–B) and two different problems (A–B and B–A). After the learning criterion was reached, training proceeded with new pairs of shapes. In the second experimental stage, every problem was presented just five times before new problems were introduced. We showed that training to criterion with just two shapes resulted in item-specific learning, whereas reducing the number of presentations to five per problem led to the formation of a same/different learning set as well as some restricted relational learning. Training with trial-unique problems in the third stage of this study resulted in the formation of an abstract concept of same/different which was indicated by a highly significant performance in transfer tests with 120 novel problems. Finally, extra-dimensional transfer of the concept was tested. The harbor seal showed a significantly correct performance on transfer tests with 30 unfamiliar pattern and 60 unfamiliar brightness same/different problems, thus demonstrating that the concept is not restricted to the shape dimension originally learned, but can be generalized across stimulus dimensions.     

Zen meditation and access to information in the unconscious

In two experiments and two different research paradigms, we tested the hypothesis that Zen meditation increases access to accessible but unconscious information. Zen practitioners who meditated in the lab performed better on the Remote Associate Test (RAT; Mednick, 1962) than Zen practitioners who did not meditate. In a new, second task, it was observed that Zen practitioners who meditated used subliminally primed words more than Zen practitioners who did not meditate. Practical and theoretical implications are discussed.     

Elicitation and punishment of intraspecies aggression by the same stimulus

Fighting responses were elicited in pairs of rats by shocks over a period of 46 days. During certain blocks of these days, “punishing” shocks were made contingent on the shock-elicited fights. Fighting frequency was reduced as a direct function of the intensity of the contingent shocks. Fighting frequency recovered completely when contingent shocks were removed.     

Attention to local form information can prevent access to semantic information.

Humphreys and Boucart (1997) have shown that when processing of local form is required for response, surrounding global information is automatically processed to a semantic level. The generality of this effect was investigated in two experiments in which the perceptual load of the relevant local form information was manipulated, as was uncertainty about perceptual load. Participants attended to a single line segment inside a picture of an animal or a vehicle and then decided which of two pictures in the target/distractor display that followed contained a line segment that matched the first in orientation. The perceptual load of the relevant local form information was either low (the matching line segment was one of the solitary line segments presented in the centre ofthe target and distractor pictures), or high (the matching line segment was part of one of the solitary letters presented in the centre of the target and distractor pictures). The semantic relations among the pictures were manipulated, and when perceptual load remained constant across trials, semantic relations affected performance in the low-load but not in the high-load condition. When perceptual load varied from trial to trial, there was no evidence of any semantic processing on either low- or high-load trials. The results suggest that in form-matching tasks, attentional priority can be given to local information, thus preventing access to semantic information derived from global shape. They further suggest that the distribution of attention is not dictated entirely by the actual perceptual demands of the relevant stimulus, indicating an important role for top-down processing.     

Using synthetic speech for remote access to information

The availability of unlimited text-to-speech synthesis systems provides the potential for remote access to databases over existing telephone systems. This paper describes some of the intelligibility and user interface problems associated with such applications and reports work aimed at understanding and solving these problems. In particular, it describes an approach to intelligibility problems based on the understanding and manipulation of listeners’ adaptation to synthetic speech, and user interface work examining use of a simulated travel information system.     

Data‐driven approaches to information access

This paper summarizes three lines of research that are motivated by the practical problem of helping users find information from external data sources, most notably computers. The application areas include information retrieval, text categorization, and question answering. A common theme in these applications is that practical information access problems can be solved by analyzing the statistical properties of words in large volumes of real world texts. The same statistical properties constrain human performance, thus we believe that solutions to practical information access problems can shed light on human knowledge representation and reasoning.     

Picture-name priming in the cerebral hemispheres: evidence for phonological access in the right hemisphere

This study investigated right hemisphere involvement in access to phonology, using a picture-naming priming paradigm where pictures and names of common objects printed in Japanese Kana were presented in succession to the same visual field or different visual fields with a stimulus onset asynchrony of 250 msec. A naming task was used for this purpose. The result showed that, when primes and targets were presented to the same visual field, facilitation for related pairs was observed in each hemisphere, with overall naming latencies being slower in the right hemisphere than in the left hemisphere. This result indicates that the prior access to phonology for a picture in the right hemisphere facilitates phonological activation of a word that names the picture in this hemisphere, suggesting that the right hemisphere is involved in access to phonology. On the other hand, when primes and targets were presented to different visual fields, there was no facilitation for related pairs with inhibition for unrelated pairs, irrespective of prime and target visual fields. It is suggested that this inhibition-dominant pattern of priming may occur due to homotopic inhibition processes proposed by N. D. Cook.