Syntactic structure modifies attention during speech perception and recognition

The present paper demonstrates the interaction of syntactic structure and speech perception with a response task which minimizes the effects of memory: reaction time (RT) to clicks during sentences. (1) In 12-word unfamiliar sentences each with two clauses, RT is relatively slow overall to clicks located at the end of the first clause but decreases as a function of clause length. Clicks at the beginning of the second clause are not affected by length of the preceding clause. (2) In familiar sentences, RT is relatively fast to clicks located at the end of a clause while RT to clicks at the beginning of clauses is relatively unaffected by familiarity. (3) RT is not fastest overall to clicks located between clauses either in novel or familiar sentences. (4) As in previous studies, the subject's subsequent judegment of the location of the click tone are towards the clause break. (5) We could find no systematic interaction between RT and subjective click location. Findings (1) to (3) are consistent with the view that perceptual processing alternates between attending to all external stimuli and developing an internal representation of the stimuli. Finding (3) is in conflict with an “information channel” view of immediate attention to speech, which would predict high sensory attention to non-speech stimuli between clauses. However, findings (4) and (5) indicate that the channel view of perception may be correct for that perceptual processing which occurs after the immediate organization of the speech stimulus into major segments.     

Variables underlying the recognition of random shapes

Speed of sorting decks of 32 cards with two alternative stimuli was measured. The stimuli were pairs of dots with attributes of distance between dots, angle of orientation of the pair, and position of the pair to the right or left of center. The attributes varied in relative discriminability and were used in all possible pair- and triple-correlated (redundant) combinations. Results showed an increase in speed of sorting with either an increase in discriminability or an increase in number of redundant attributes. It is argued that the increased speed with addition of redundant attributes is due both to a selective serial processing of attributes (requiring attribute separability) and to an increased discriminability with combined attributes (requiring attribute integrality).     

A note on mathematical models for learning

It is shown that a rational learning curve developed by Estes for paired associate learning is a special case of a more general function. The latter is the product of two functions and assumes that the discovery and fixation aspects of learning are independent. The indications are that the form of one of the functions has not been tested sharply by Estes in the paired associate learning setting.     

Book reviews

The Journal of Value Inquiry -     

Cation and anion contributions to gustatory quality of simple salts

Curves of mean percentages of the four gustatory quality responses as a function of concentration of solutions of LiCl, KCl, lithium sulfate, and potassium sulfate were evaluated as to the relative contributions of the cation and anion to the quality. It was concluded that chloride ion, and sulfate ion to a lesser degree, were responsible for the salty quality. In the mid-range concentrations, potassium ion was responsible for the bitter quality, and lithium ion, by means of an ion-soliient interaction; was responsible for the sour quality reported. At the very low concentrations, at which all salts tested evoked sweet responses, a structure produced by a solvent-cation interaction was assumed to be responsible. The details of the presumed structure are still to be clarified. Although one ion in each salt is primarily responsible for a particular quality over a given concentration, the other ion usually modifies the effect.     

Cortical steady-potential shifts in conditioning

Cortical steady-potential shifts obtained from nonpolarizing electrodes chronically implanted in freely moving cats and rats reveal cortical activation related to urgency of response to unconditional and conditional stimuli. Such shifts appear relatively independent of activation in the rhythmic electrocorticogram and are related to higher levels of activation. Shifting is found to be modulated by drive and level of learning, suggesting a correlation with the proposed reaction potential of Hull. Both approach and avoidance “urgency” are reflected in the onset slope and amplitude of SP shifts in a manner suggesting modulation of cortical activation by the effects of behavioral regulation of stimulus conditions.     

The effects of coding procedure on human information transmission

Three different coding schemes, i.e., transformations between stimuli and responses, were used in a continuous information transmission situation. The stimuli were groups of binary digits and S was required to transform these into verbal equivalents of combinations formed by taking various sets of the English letters. Three codes, one based on communication theory, one based on Miller’s (1956) chunking hypothesis, and a combination of the first two were used. In addition, two levels of stimulus redundancy, zero and 0.5 were used. Time to complete the task and errors were the de-pendent variables. The Ss were run for twelve days. The basic result was that Ss transmitted information at a constant rate regardless of the code or redundancy level used.