Change in the event-related skin conductivity: an indicator of the immediate importance of elaborate information processing?]

In recent psychophysiological conceptualizations of the orienting response (OR) within the framework of information processing, the OR is increasingly considered a "call for processing resources", something which is especially inferred from variations in the event-related skin conductance response (SCR). The present study, therefore, was concerned with certain implications arising from this framework or perspective, particularly in regard to the question of whether stimuli eliciting skin conductance responses obligatorily receive/evoke processing priority or not. In order to examine whether these electrodermal responses denote a capturing of attention or merely a call for processing resources, short (1 s) pure sine tones of 65 dB with sudden onset (commonly used as orienting stimuli) were inserted in a reaction time paradigm with an additional memory load. This demand was primarily given because memory processes play a key role in theories of orienting and habituation. The task was run under two different conditions of complexity, factorially combined with a novelty variation of the added auditory stimuli. The results revealed a substantial deterioration of task performance subsequent to the occurrence of the tones, which, however, was dependent on task complexity and on novelty of the tones. The task impairment is particularly remarkable as subjects were asked to avoid distractions by paying attention to the task and as the tones were introduced as subsidiary and task-irrelevant. Together with the missing effects of task complexity on phasic and tonic electrodermal activity, results suggest that information-processing conceptualizations of the OR can only be a meaningful heuristic contribution to theoretical developments about human orienting and its habituation if the setting of processing priority, its conditions, as well as its implications are adequately taken into account. In addition, it seems to be promising to consider the strength of the SCR as an index of urgency of elaborate, attention-demanding processing and not as a peripheral physiological manifestation of the OR, or, respectively, of a call for unspecific processing resources. Such a view would also do justice to the aspect of prioritization. The sufficient conditions for an OR's occurrence could, in this context, be equated with, among others, some of those which activate a mechanism subserving selective attention and, as a possible result, which lead to further and more elaborate processing of potentially important information.     

Discrimination learning of rotated faces: a Markov analysis of coding and association processes]

30 subjects participated in a discrimination experiment learning face-letter associations under four rotation conditions (45 degrees, 90 degrees, 135 degrees, 180 degrees). Under each condition two thirds of the faces were presented twice, upright and rotated away from the vertical; the remaining faces were presented once, upright or rotated. Learning is described by a joint Markov model: For faces that are presented twice it assumes a separate association and encoding process (two-stage-model), for faces that are presented once it assumes an association process (all-or-none-model). The Markov model fits the data for all four rotation conditions. The angle of rotation does not affect learning for faces that are presented once. For faces that are presented twice it influences both the association and the encoding process. For the angles employed, the effect of rotation can be approximated linearly. The results suggest that the encoding of a rotated face differs increasingly from an upright face as a function of these angles of rotation. This confirms analogous conclusions from mental rotation experiments.     

Degree of learning,interpolated tests,and rate of forgetting

The purpose of the two experiments reported here was to observe the effects of degree of learning, interpolated tests, and retention interval, primarily on the rate of forgetting of a list of words, and secondarily on hypermnesia for those words. In the first experiment, all the subjects had one study trial on a list of 20 common words, followed by two tests of recall. Half of the subjects had further study and test trials until they had learned the words to a criterion of three correct consecutive recalls. Two days later, half of the subjects under each learning condition returned for four retention tests, and 16 days later, all the subjects returned for four tests. Experiment 2 was similar, except that all the subjects had at least three study trials followed by four recall tests on Day 1, intermediate tests were given 2 or 7 days later, and they all had final tests 14 days later. The results showed that rate of forgetting was attenuated by an additional intermediate set of tests but not by criterion learning. Hypermnesia was generally found over the tests that were given after a retention interval of 2 or more days. The best predictor of the amount of hypermnesia over a set of tests was the difference between overall cumulative recall and net recall on the first test of the set.     

The effects of syntactic structure on letter detection in adjacent function words

In the present study, we examined letter detection in very frequent function-word sequences. It has been claimed that such sequences are processed in a unitized manner, thus preempting access to their constituent letters. In contrast, we showed that letter detection in the words for and the (1) was no more difficult when the words appeared in adjacent locations in a sentence (familiar) than when they appeared apart (less familiar sequence) and (2) was contingent upon the words' syntactic roles within the phrase. Thus, letter detection in for was easier when the sequence was separated by a clause boundary than when the words were part of the same clause. The advantage derived from clause separation was strongest when a comma divided clauses. These results challenge the unitization account of the "missing-letter" effect in common phrases and support a position where this phenomenon is seen to reflect the extraction of phrase structure during reading.     

Supernatural beliefs,natural kinds,and conceptual structure

This article presents cross-cultural evidence in support of the notion that adults' natural kind concepts are theory based but may be informed by knowledge/belief systems other than the biological. Three groups of subjects from western Nigeria--rural, urban, and elite--participated in the study. Subjects heard stories describing alterations of appearance; that is, one natural kind was made to resemble another in both ritual and nonritual contexts. Subjects then were required to judge the identity of the altered item and to give an explanation for the category judgment. It was predicted that subjects would make more nonpreservation-of-identity category judgments supported by supernatural explanations in the ritual contexts and that subjects' use of supernatural explanations would reflect the extent of their engagement with the supernatural. The first prediction was borne out; the second prediction was only partially supported. Discussion of the results emphasizes the importance of exploring the role of sociocultural factors in conceptual structure.     

Sentence encoding and implicitly activated memories

Some words have fewer direct associates than others, and, when words varying in set size are studied in a list-learning task, those with smaller sets are more likely to be recalled. This set-size effect is found in cued recall when the words are studied in the absence of related words, but not when studied in the presence of related words. Related words provide context and theoretically inhibit irrelevant associates. The present research determined that set-size effects are found when words are encoded in sentence contexts. In contrast to list-learning experiments, the results of three experiments found such effects even when lexically related words were present in the sentences. Other findings indicated that target-set-size effects were determined by the proximity of related words in the sentence and the nature of the test cue. The results are discussed in relation to a model for explaining set-size effects and to selective findings from the sentence-comprehension literature.     

The representation and integration in memory of spatial and nonspatial information

A series of experiments investigated whether people could integrate nonspatial information about an object with their knowledge of the object's location in space. In Experiments 1 and 3, subjects learned the locations of cities on a fictitious road map; in Experiments 2, 4, and 5, subjects were already familiar with the locations of buildings on a campus. The subjects then learned facts about the cities on the maps or the buildings on the campus. The question of interest was whether or not these nonspatial facts would be integrated in memory with the spatial knowledge. After learning the facts, subjects were given a location-judgment test in which they had to decide whether an object was in one region of the space or another. Knowledge integration was assessed by comparing levels of performance in two conditions: (a) when a city or a building name was primed by a fact about a neighboring city or building, and (b) when a city or a building name was primed by a fact about a distant city or building. Results showed that responses in Condition a were faster or more accurate, or both faster and more accurate, than responses in Condition b. These results indicate that the spatial and nonspatial information were encoded in a common memory representation.     

Cuing effects and associative information in recognition memory

Item recognition requires discrimination of studied words from nonstudied words. Associative recognition requires subjects to discriminate studied word groups from recombinations of words from different groups. Cued recognition requires the same old-new discrimination as item recognition, but list items are presented as cues along with the test item. The results from three experiments show (1) little or no effect of cuing for low-frequency words, but (2) positive cuing effects for high-frequency words; (3) increasing levels of overall performance with increases in study time, but (4) unchanging effects of cuing with study time; and (5) stronger positive cuing effects for two cues than for one cue. Five models (Independent Cue Model, Matrix model, MINERVA 2, SAM, and TODAM) were fit to the data of Experiment 1. Each model has trouble with at least one aspect of the results. Theoretical implications and modifications are discussed at length.     

Acoustic analysis in the differentiation of Parkinson's disease and major depression

In its early stages, Parkinson's disease (P.D.) may be difficult to distinguish from major depression (M.D.) leading to inappropriate management. Both illnesses are characterized by psychomotor retardation. The neurovegetative symptoms used to diagnose M.D. are not specific and in P.D. may be due to the physical illness itself. Currently, differentiation of the two disorders relies on subjective clinical observation. Improved diagnostic accuracy based on more objective data is needed. To this end, this study used computerized acoustic analysis to contrast speech patterns in P.D. and M.D. The sample consisted of 30 P.D. patients without depression or dementia, 30 patients with uncomplicated M.D., and 31 normal controls, each 60 years of age or over. Of the acoustic variables studied, M.D. patients had significantly reduced rates of speech compared with P.D. patients. The data suggest that this temporal measure of speech may be useful in the differentiation of P.D. and M.D.     

Word-finding abilities of three types of aphasic subjects

Word-finding difficulties are often observed among different types of aphasic patients. This investigation analyzed the word-finding abilities of 30 aphasic subjects (10 Broca's, 10 Wernicke's, and 10 anomic). Forty nouns counterbalanced according to word length and frequency of occurrence in English language usage were used as stimuli and presented through four modalities (oral expression, writing, auditory comprehension, and reading comprehension). It was expected that patterns of word finding abilities would help in the classification of the different types of aphasia. In addition, long words and less frequently occurring words in English language usage should prove more difficult in word-finding ability, regardless of modality. The results of this study found long words and less frequent words were more difficult for aphasic subjects. Among the modalities, long words were significantly harder than short words for the writing modality only. It was also found that semantic errors were the most common errors for all types of aphasic subjects. Broca's subjects produced significantly moreno response errors in oral expression; Wernicke's subjects produced significantly more semantic and phonemic errors in reading comprehension; and, Wernicke's subjects produced significantly more unrelated errors in both oral expression and reading comprehension. Clinical implications were also discussed.The present study was based on a doctoral dissertation completed at the City University of New York in partial fulfillment of the requirements of the doctoral degree in Speech and Hearing Sciences by the first author under the direction of the second author. The authors wish to thank Dr. Louis J. Gerstman for his assistance with the statistical analysis of this research and Dr. Robert Goldfarb for all his helpful suggestions and editorial comments.