An olfactory investigation of the compatibility of oddity instructions with the design of a 3-AFC signal detection task

There are two principal differences between the Triangular Method and the 3-Alternative Forced-Choice (3-AFC) procedure originating from the theory of signal detection. These are the instructions given and the types of three-stimulus sets (‘triangles’) presented to the subject.In the Triangular Method the subjects are instructed to select the odd stimulus from each triangle presented, whilst in the 3-AFC task the subject must either select the strongest or identify the weakest stimulus.The triangles presented in the Triangular Method sometimes contain two physically weak stimuli plus one stronger, and at other times two strong stimuli plus one weaker. In contrast, in a 3-AFC experiment all the triangles comprise either two weak plus one stronger, or two strong plus one weaker stimulus.Previous research has shown that the parameter d' is invariant with the two procedures, if the appropriate models are used for conversion of proportions of correct responses into corresponding values of d'.The present experiments provide evidence that the Triangular Method instructions (to select the odd stimulus) used in combination with the 3-AFC task design (using three types of triangles) does not result in biased estimates of d'. In addition, it was shown that even after a large number of presentations the value of d' remained stable, which supports the notion of stability of the decision rule implied by the oddity instructions.     

Recognition hypermnesia: The growth of recognition memory (d') over time with repeated testing

This study sought to determine whether recognition hypermnesia (unforgetting) might be obtained over time with repeated testing of recognition memory. Four types of stimuli were investigated: pictures or words (captions) from configured (funny) or non-configured (non-funny) cartoons. Three recognition tests, each comprising the same stimulus and distractor items, were successively administered after the presentation of a large set of captioned cartoons. Silent think intervals of 5 min were interpolated between recognition tests. Recognition hypermnesia, measured by increasing d' estimates of accessible recognition memory, was obtained with the pictures from configured (funny) cartoons but not with any of the other groups.     

Effects of a coactor's prediction on latencies to predict and indentify stimuli

On each of 300 trials E's confederate (C) verbalized which of two stimuli would occur; then S made a prediction. Following each presentation, S and C pulled a trigger to identify the stimulus. Two latencies were measured: the interval between C's and S's prediction (prediction time), and the interval between stimulus presentation and S's identification response (choice RT). Prediction times were significantly shorter when S's prediction agreed rather than disagreed with C's prediction, when S's preceding prediction was correct rather than incorrect, and when S was female rather than male. Choice RT was influenced by distributions of C's stimulus predictions and C's prediction outcomes in directions supporting an expectancy model.     

Working Memory for Temporal and Nontemporal Events in Monkeys

This is the first report that introduces appropriate behavioral tasks for monkeys for investigations of working memory for temporal and nontemporal events. Using several behavioral tests, the study also shows how temporal information is coded during retention intervals in the tasks. Each of three monkeys was trained with two working memory tasks: delayed matching-to-sample of stimulus duration (DMS-D) and delayed matching-to-sample of stimulus color (DMS-C). The two tasks employed an identical apparatus and responses and differed only in the temporal and nontemporal attribute of the stimuli to be retained for correct performance. When a retention interval between the sample and comparison stimuli was prolonged, the monkeys made more incorrect responses to short samples in the DMS-C task, suggesting “trace decay” of memory for short stimuli. However, the same monkeys showed no such increase in incorrect responses to short samples in the DMS-D task, suggesting active coding of temporal information, that is, the length of stimulus duration, during the retention interval. When variable lengths of samples were presented with a fixed retention interval, the monkeys made more incorrect responses when length differences between short and long samples were small in the DMS-D task, but not in the DMS-C task. This suggests that the codes of working memory retained in the DMS-D task were not absolute (analogical) but rather were relative (categorical) and related to differences in the duration of the samples.     

A model of three-choice discrimination learning under complete and incomplete feedback conditions

The Bower and Trabasso model of concept identification was extended to cover problems in which three stimuli were presented simultaneously and S pointed to the one he thought was correct. The E gave complete feedback by indicating the correct stimulus, or incomplete feedback by saying “correct” or “wrong.” The model accurately accounted for the significant difference in total errors between the two feedback conditions by incorporating process assumptions reflecting the logical difference in information content of the two types of feedback. Using a single set of parameter estimates, the model made satisfactory quantitative predictions of several statistics for both feedback conditions. Some deviations from the model's predictions were found in the length of terminal error runs, indicating that Ss were possibly using memory more extensively than posited by the model.     

Reinforcer frequency and restricted stimulus control.

Stimulus control was evaluated in 3 individuals with moderate to severe mental retardation by delayed identity matching-to-sample procedures that presented either one or two discrete forms as sample stimuli on each trial. On pretests, accuracy scores on one-sample trials were uniformly high. On two-sample trials, the correct stimulus (i.e., the one that subsequently appeared in the comparison array) varied unpredictably, and accuracy scores were substantially lower, suggesting that both sample stimuli did not exert stimulus control on every trial. Subjects were then given training sessions with the one-sample task and with a new set of four stimuli. For two of the stimuli, correct matching responses were followed by reinforcers on a variable-ratio schedule that led to a high reinforcer rate. For the other two stimuli, correct responses were followed by reinforcers on a variable-ratio schedule that led to a substantially lower reinforcer rate. Results on two-sample tests that followed showed that (a) on trials in which comparison arrays consisted of one high reinforcer-rate and one low reinforcer-rate stimulus, subjects most often selected the high-rate stimulus; and (b) on trials in which the comparison arrays were either two high reinforcer-rate stimuli or two low reinforcer-rate stimuli and the samples were one high reinforcer- and one low reinforcer-rate stimulus, accuracy was higher on trials with the high-rate comparisons. These results indicate that the frequency of stimulus control by high reinforcer-rate samples was greater than that by low reinforcer-rate samples. Following more training with the one-sample task and reversed reinforcement schedules for all stimuli, the differences in stimulus control frequencies on two-sample tests also reversed. These results demonstrate experimental control by reinforcement contingencies of which of two sample stimuli controlled selections in the two-sample task. The procedures and results may prove to be relevant for understanding restricted stimulus control and stimulus overselectivity.     

Response selection,sensitivity, and taste-test performance

Tasters selected the odd stimulus from among sets of three samples of party dip. Two samples came from one batch, and one sample came from another batch. The physicochemical difference between the batches consisted of the presence or absence of added salt. Two different tests of discriminability were undertaken by the same subjects with the same stimuli: the triangle test and the three-alternative forced-choice (3-AFC) method. Although different numbers of correct selections were obtained in the two tasks, an index of discriminability,d’, had the same value when the data were analyzed in accordance with the Thurstone-Ura and signal-detection models, respectively. The average data support Frijters’s (1979b) contention that different models of the discrimination process are appropriate to the results of the triangular and the 3-AFC procedures. Further analysis of the data revealed that discrimination was poorer for trios containing one physicochemically weak stimulus and two stronger stimuli than it was for trios containing one stronger stimulus and two weak stimuli. A two-signal 3-AFC task was undertaken by some subjects, andd’ estimates from this task were lower than expected on the basis of performance in the other tasks.     

Associations to unfamiliar words: Learning the meanings of new words

Five experiments were designed to examine whether subjects attend to different aspects of meaning for familiar and unfamiliar words. In Experiments 1–3, subjects gave free associations to high- and low-familiarity words from the same taxonomic category (e.g.,seltzer:sarsparilla; Experiment 1), from the same noun synonym set (e.g.,baby:neonate; Experiment 2), and from the same verb synonym set (e.g.,abscond:escape; Experiment 3). In Experiments 4 and 5, subjects first read a context sentence containing the stimulus word and then gave associations; stimuli were novel words or either high- or low-familiarity nouns. Low-familiarity and novel words elicited more nonsemantically based responses (e.g.,engram:graham) than did high-familiarity words. Of the responses semantically related to the stimulus, low-familiarity and novel words elicited a higher proportion of definitional responses [category (e.g.,sarsparilla:soda), synonym (e.g.,neonate:newborn), and coordinate (e.g.,armoire:dresser)], whereas high-familiarity stimuli elicited a higher proportion of event-based responses [thematic (e.g.,seltzer:glass) and noun:verb (e.g.,baby:cry)]. Unfamiliar words appear to elicit a shift of attentional resources from relations useful in understanding the message to relations useful in understanding the meaning of the unfamiliar word.     

A new processing model for predicting performance on Pascual-Leone's test of M-space

A new model is proposed for explaining children's performance on Pascual-Leone's test of M-space. The model differs from Pascual-Leone's in three regards. (1) It assumes that children do not stop sampling a compound stimulus until every simple stimulus in their field of attention has already been noticed and responded to. (2) It assumes that the probability of sampling different combinations of simple stimuli conforms to the laws of Maxwell-Boltzman statistics rather than Bose-Einstein statistics. (3) It assumes that children's ability to detect all the simple stimuli in a compound stimulus is highly dependent both on the relative saliencies of the simple stimuli and on the length of time for which the compound stimulus is exposed. Using the developmental values of M hypothesized by Pascual-Leone, and standard techniques of computer simulation, the new model is used to generate theoretical performance curves for children at four different age levels and seven different levels of stimulus complexity. It is shown that the predicted performance curves for an exposure time of 5 sec provide a reasonable fit to the data originally reported by Pascual-Leone (1970), and that the predicted performance curves for an exposure time of 10 sec provide a reasonable fit to data obtained more recently by Parkinson (1976). Finally, it is shown that the order of children's responses as well as the number of their responses can be predicted. Two conclusions are drawn. (1) The new processing model offers a viable alternative to the model originally proposed by Pascual-Leone. (2) Regardless of which processing model is employed, the M-values originally postulated by Pascual-Leone are valid.     

The relation of discrete stimuli can be integrated despite the failure of conscious identification

ABSTRACT

The integration of the sameness or difference of two unconscious stimuli occurs and affects behaviour without subjective visual consciousness. Yet, intermittent stimulus awareness or a process simpler than integration could also account for these results. In a masked go/no-go task, participants provided or withheld a response based on the same/different relation of two stimuli. Post-trial performance on a discrimination task was used to classify invisible stimuli, providing an objective criterion of awareness. Stimulus pairs with a No-go-associated relation showed reduced and slower responding even when those stimuli were incorrectly discriminated and presumably unconscious. Due to the large set of stimuli, this effect is unlikely to be due to response mapping or action triggers. The integration of the relation of discrete stimuli is a cognitive function that is not dependent upon visual awareness, in the form of conscious identification, to occur.     

Comparing the effects of two correction procedures on human acquisition of sequential behavior patterns

Thirty-one college undergraduates learned to touch abstract stimuli on a computer screen in arbitrarily designated “correct” sequential orders. Four sets of seven stimuli were used; the stimuli were arrayed horizontally on the screen in random sequences. A correct response (i.e., touching first the stimulus designated as first) resulted in that stimulus appearing near the top of the screen in its correct sequential position (left to right), and remaining there until the end of the trial. Incorrect responses (i.e., touching a stimulus out of sequence) terminated the trial. New trials displayed either the same sequence as the one on which an error had occurred (same-order correction procedure), or a new random sequence (new-order correction procedure). Whenever all responses occurred in the correct sequence, the next trial displayed a new random sequence. Each phase ended when five consecutive correct response sequences occurred. Initially, the same-order correction procedure increased control by the position as well as by the shape of the stimuli; also, it produced more errors, more total trials, more trials to mastery, and more individual patterns of reacquisition than were produced by the new-order procedure.     

Effects of the temporal relationship of feedback and stimulus information upon discrimination-learning strategies

Second grade Ss and college students were tested under three conditions of the temporal relationship of feedback and stimulus information. In one condition (/+3) feedback was delivered immediately upon S's response while the stimuli were still in view. In another (/0) feedback was also immediate but stimuli were extinguished immediately upon S's response. In the third condition (/?3), stimuli were extinguished immediately upon response and feedback was delayed 3 sec. Major findings among the children were (a) Ss of all conditions coded information at the same (high) average efficiency, (b) Ss of conditions /0 and /?3 recoded with significantly less efficiency than those of /+3, and (c) Ss in condition /+3 manifested primarily efficient information-processing strategies, those in condition /0 showed intermediate performance, and those of condition /?3 showed relatively primitive stereotyped behavior. Among adult Ss performance was uniformly high with little effect on any response measure investigated.     

Simple visual reaction time,personality and strength of the nervous system: A signal-detection theory approach

Eysenck (1967) has reviewed evidence which suggests that introverts have a higher level of arousal than extraverts. Moreover, Gray (1967) has proposed that introverts have weak nervous systems, in the Russian terminology. Studies of simple reaction time such as that of Mangan and Farmer (1967) have posed problems for these views, but it is suggested that this may have been due to criterion differences between introverts and extraverts. In the present study a simple visual reaction-time task and a signal-detection task were conducted side by side. No significant differences between introverts and extraverts were found in measures of strength derived from the former, or measures of criterion derived from the latter. However, high N Ss were found to have a significantly lower value for Nebylitsyn's index of the slope of the reaction time/stimulus intensity function, thus supporting the view that high N Ss have relatively weak nervous systems.     

Stimulus control in a simple instrumental task: The role of internal and external stimuli

Two experiments using rats in a straight alley runway task tested the hypothesis that standard stimuli such as tones and lights (“external” stimuli) and schedule-generated aftereffect stimuli (“internal” stimuli) operate similarly and are similarly subject to the compounding rules specified by R. A. Rescorla and A. R. Wagner (In A. Black & W. Prokasy (Eds.), Classical conditioning II: Current theory and research. New York: Appleton-Century-Crofts, 1972). The experimental task was an instrumental analog of the classic blocking experiment (L. J. Kamin, In M. R. Jones (Ed.). In Experiment 1, blocking of an external discriminative stimulus by a different asymptotic discrimination was accomplished. In Experiment 2, blocking of an internal stimulus discrimination by an asymptotic external stimulus discrimination was obtained. The present results support the view that internal and external stimuli are indeed similar and function in the same manner with regard to blocking of stimulus control.     

Children's component selection with varying degrees of training

With the component selection measure developed by Hale and Morgan (1973), children's use of selective attention was assessed at six levels of learning, ranging from undertraining to overtraining, and this function was examined at each of ages 4, 8, and 12. It was found that, as the children learned the task, they maintained a relatively wide focus of attention, acquiring information about both features of the stimuli, color and shape. Thus, contrary to the model under investigation, the children did not exercise a high degree of selectivity as they approached mastery of the task; nor did overtraining produce the expected “broadening” of attention, as the children acquired little stimulus information beyond the point at which criterion had been reached. The data were interpreted to be more consistent with a model that assumes the bulk of stimulus learning to occur prior to task mastery.     

The impact of stimulus-specific practice and task instructions on response congruency effects between tasks

In task switching experiments participants have to respond to the same set of stimuli while task instructions vary (e.g., digit stimuli are assigned to left- or right-sided key presses by means of magnitude vs. parity classification). Response congruency effects denote worse performance for a stimulus, which is associated with different responses in the two tasks as compared to a stimulus, which is associated with the same response. Previous research suggests that such effects reflect direct links between stimuli and responses acquired in the course of experimental practice. In the current study we investigated the impact of stimulus-specific practice and task instruction by reversing the S–R mapping of one task (Experiment 1) or replacing one task with a new one (Experiment 2) in the second half of an experimental session. Consistent with the direct link account, S–R links practiced during the first half of the experiment largely determined congruency effects despite altered task instructions. Furthermore, the results suggest that previously practiced S–R links (a) can be relatively quickly overwritten by practicing a novel S–R mapping, and (b) are subject to passive decay when no longer in use.     

On the young child's use of lexis and syntax in understanding locative instructions

The ability of two and three year old children to comprehend in, on and under was tested in five contexts. In the first context, where responses did not depend on the child manipulating the experimental objects, responses were invariably correct except for some difficulty with under in the youngest subjects. In the other four contexts, which did involve manipulation of the objects by the child, responses varied as a function of the noun phrases used to refer to the experimental objects which themselves remained the same across different contexts. The result suggest that the young child's comprehension of instructions involves an interaction between aspects of the instruction's lexis and syntax and the child's construal of context.     

How a thing is called—A study of mothers' and children's naming

Mothers' selections of category names in object-naming tasks were examined using the levels of categorization defined by Eleanor Rosch (E. Rosch. In T. Moore (Ed.), Cognitive development and the acquisition of language, New York: Academic Press, 1973. E. Rosch. In E. Rosch & B. Lloyd (Eds.), Cognition and categorization. Hillsdale, N.J.: Erlbaum, 1978. E. Rosch, C. Mervis, W. Gray, D. Johnson, & P. Boyes-Braem. Cognitive Psychology, 1976, 8, 382–439). The effect of three variables—Presentation Context, Taxonomy, and Age (of person for whom mother was naming the items)—on mothers' choice of category names, was also investigated. The stimuli were 36 photographs of common concrete objects representative of four taxonomies. Forty mothers named the stimulus items for their 2-year-olds (N = 20), for their 4-year-olds (N = 20), and for the Experimenter. The category labels that children of both ages used when naming the same items, and mothers' independent predictions of the names their children would use in the naming task, were recorded. Contextual factors were found to have a primary role in determining mothers' selections of category names and the three independent variables had a complex and dynamic effect on mothers' naming practices.     

Newborn habituation to visual stimuli: a sex difference in novelty detection

Thirty-six newborn human infants were repeatedly exposed to one of two visual stimuli, a four-square or 144-square black and white checkerboard target, until a set criterion of habituation was demonstrated, as measured by a decrement in visual fixation time. When the habituation criterion was reached, independent groups of Ss were either presented with the same target or with a target of either moderate or large discrepancy from the standard habituation stimulus. Results indicated that (1) there was habituation of visual attention, which replicated previous findings, and suggests that some infants soon after birth are capable of storing simple visual information, and (2) following habituation female infants displayed greater recovery of attention than male infants when the moderate stimulus change was introduced.