Proportion Of Correct Responses Research Articles

Categorical Perception of Illusory Contour Defined Shapes

Categorical perception (CP) is the phenomenon when people are better able to distinguish between stimuli of different categories than between stimuli of the same category and it appears for innate and learned stimuli of various sensory modalities. We tested if CP occurs also for illusory contour stimuli. First, in an ABX paradigm the shape discrimination capacity of subjects was tested for convex (‘fat’) or concave (‘thin’) Kanizsa-square-like shapes (cf Rubin, 1996 Perception25 Supplement, 3; pre-category-learning test). The proportion of correct responses and response latency were measured. Second, subjects were instructed that every stimulus belongs to either the ‘fat’ or the ‘thin’ category, and they were trained to categorise the individual stimuli using a 2AFC paradigm with corrective feedback until 90% of correct responses. Third, we measured the shape discrimination capacity of subjects, by repeating the first ABX paradigm (post-category-learning test). Comparison of the ratio of correct responses in the post/pre discrimination tests showed that discrimination of illusory shapes of different categories is enhanced but discrimination of members of the same category is made more difficult by category training. In a second experiment, by increasing the physical differences between the extreme ‘fat’ and extreme ‘thin’ stimuli (increased range of the opening-angle of the Kanizsa-square inducer pacmen), we made the categorisation task easier for the subjects and tested if discrimination capacity is altered by the modified difficulty of the categorisation task. We discuss the effect of difficulty on CP and the relation of illusory CP to that of real luminance contour stimuli.

Scalp Topography of Event-related Brain Potentials and Cognitive Transition during Childhood

This study examined the relation between cognitive development and the ontogenesis of event-related brain potentials (ERPs) during childhood. First, the level of cognitive development was assessed in girls between 5 and 7 years of age with a standard Piagetian conservation kit. Then these children performed 2 experimental tasks: a visual selective attention (oddball) task and an experimental analogue of the Piagetian conservation of liquid quantity task. The oddball task required the child to count silently the number of rare stimuli presented in a series of frequent stimuli. The ERPs elicited in this task showed a positive wave with a centroparietal scalp distribution and a maximum amplitude at around 600 ms poststimulus. In the experimental analogue of the conservation of liquid quantity task, the child was presented with a choice stimulus requiring a left- or right-hand button press. The proportion of correct responses discriminated successfully between conservers and nonconservers as established by traditional Piagetian assessment procedures. The ERPs obtained in the experimental analogue of the conservation task were characterized by a broad positivity with a centroparietal scalp distribution. The broad positivity discriminated significantly between nonconservers and conservers but not between age groups. These findings received additional support from topographic and symmetric dipole analyses of the ERPs. The results of the dipole analysis suggested more anterior ERP sources for the nonconservers during the early part of stimulus analysis and more lateralized ERP sources for conservers during the later part of information processing. It is concluded that ERPs may provide a window on the relation between brain maturation and stage-wise cognitive development.

Effects of Mood Induction on the Recognition Memory of Word Types

Substantially induced sad or happy mood was created through the use of the Velten Depressed or Elated self-reference statements. Emotionally pleasant words were then presented on the computer screen. 24 hours later, either the same or opposite mood was induced prior to the presentation of exact match, mood match, and mood opposite words. Reaction times were faster, and the proportion of correct responses was greater for the exactly matched words. Experimentally induced mood bore some relationship to the speed but not to the accuracy of recognition. The serious decrement of 40% was noted for accuracy for words with ratings of emotion similar to those of the training words. This decrement was based on false identification of the previously encoded words. This suggests that, although semantic memory is cognitively inaccurate, it is affectively accurate

Uncontrolled T Intersections: Who Should Yield?

A questionnaire is distributed to licensed drivers in Iowa, asking questions regarding assignment of right‐of‐way at uncontrolled T intersections. A majority of respondents gives incorrect answers. Age is determined to be related to correctness of response, with older drivers having a greater proportion of correct responses than younger drivers. Traffic and accident data are collected for randomly selected uncontrolled T and four‐legged intersections. The accident rates calculated for these intersections are 0.251 and 0.733 accidents per million entering vehicles, respectively. The difference in the rates is found to be significant at the 0.005 level. It is concluded that a difference exists between drivers' perception and legal right‐of‐way assignment at uncontrolled T intersections. A recommendation is made to change the law in Iowa to give the right‐of‐way at uncontrolled T intersections to vehicles on the nonterminating roadway, and for research on nationwide uniformity in the laws governing T interse...

High-resolution facial feature saliency mapping.

For recognition of a target there must be some form of comparison process between the image of that target and a stored representation of that target. In the case of faces there must be a very large number of such stored representations, yet human beings seem able to perform comparisons at phenomenal speed. It is possible that faces are memorized by fitting unusual features or combinations of features onto a bland prototypical face, and such a data-compression technique would help to explain our computational speed. If humans do indeed function in this fashion, it is necessary to ask just what are the features that distinguish one face from another, and also, what are the features that form the basic set of the prototypical face. The distributed apertures technique was further developed in an attempt to answer both questions. Four target faces, stored in an image-processing computer, were each divided up into 162 contiguous squares that could be displayed in their correct positions in any combination of 24 or fewer squares. Each observer was required to judge which of the four target faces was displayed during a 1 s presentation, and the proportion of correct responses for each individual square was computed. The resultant response distributions, displayed as brightness maps, give a vivid impression of the relative saliency of each feature square, both for the individual targets and for all of them combined. The results, while broadly confirming previous work, contain some very interesting and surprising details about the differences between the target faces.

Painfulness decreases the discriminability of electric shock.

Two experiments were designed to investigate the relation between the reported painfulness and the discriminability of pairs of electric shocks for which the ratio between the higher and the lower intensity was held constant. In both experiments, subjects first gave category ratings of the painfulness of single shocks in the range 40 to 4.8 mA. Then, in a discrimination experiment, they were required to identify the stronger of a pair of intensities presented in succession. The proportion of correct responses (Experiment 1) or the proportion of area under the receiver operating characteristic (Experiment 2) increased between a low-intensity pairing and a medium-intensity pairing and decreased between a medium-intensity pairing and a high-intensity pairing for subjects who rated the highest intensities as strongly painful. Subjects who gave moderate- or weak-pain ratings for the high-intensity shocks showed no significant increase or decrease in accuracy between the medium- and high-intensity pairings. Time-order errors were observed in Experiment 1. The proportion of trials on which the second stimulus of the pair was identified as the stronger increased monotonically as a function of stimulus magnitude. The results are discussed in the context of psychological assessment of analgesic procedures.

The role of selected auditory skills in the misarticulation of /s/, /r/ and /theta/ by third grade children.

AbstractIn this study, the relationship of echoic memory, speech sound discrimination and speed of auditory processing to the consistency of correct production of certain speech sounds was examined. Thirty-seven children representing third grade normal and Is I, Irl and Idl defective speakers served as subjects. Each subject listened to tapes of pairs of vowel-consonant-consonant-vowel bisyllables under each of three conditions: (1). 25 seconds between bisyllables; (2) 2.0 seconds between bisyllables; and (3) 10.0 seconds between the bisyllables in each pair. The subjects' task was to determine whether the bisyllables in each pair were the same or different. Results of statistical analyses on the proportion of correct responses indicated that production errors on different sounds may be associated with different auditory skills. The findings are related to previous investigations of speech sound discrimination skills in articulatory defective children. Clinical implications also are discussed.

Inversions in true/false and in multiple choice questions -- a new form of item analysis.

Summary Total ignorance is expressed not by consistently selecting the wrong answers in a true/false or multiple choice examination, but rather by making a random choice from all the alternatives available, resulting in a predictable proportion of correct responses. When a significant majority of students answers incorrectly in a true/false question, it must therefore be concluded that this is not the result of ignorance, but of some factor which has led to their deliberately choosing the wrong answer. This situation has been termed an ‘inversion’. Of 2057 true/false examination questions set in this department over the past 3 years, 140 (6.8%) were found to be ‘inverted’. In about one third of these cases the ‘inversion’ was found to be due to a wrong model answer, an ambiguous or misleading question, or to incorrect teaching. The remaining two-thirds of the ‘inversions’ could be ascribed to attempts to work out the answer from inadequate or inappropriate first principles. It has been our policy to delete all ‘inverted’ questions from the examination (unless the model answer needed to be changed), because the score obtained when the students deliberately chose the wrong answer is less than the score they would have obtained had they been totally ignorant and had ventured a guess or had chosen not to answer the question. This concept can also be applied to multiple choice questions.

Reversal errors in strong, average, and weak letter namers.

Four hundred nine first graders were asked to name the letters of the lowercase alphabet presented in fixed, nonalphabetical order. In going from the weak to the average to the strong groups of letter namers, the proportion of correct responses for each letter increased. However, an examination of their errors showed that the more competent the group was in letter naming, the higher the proportion of reversal errors in wrong responses (p < .001). It was concluded that letter reversal errors are not necessarily indicators of a basic perceptual or cognitive deficit.

Rekitting the Wechsler Paired-Associate Task: the Waterford Index.

The Waterford Index provides a new scoring system for the Wechsler paired-associate task. Item performances across successive trials were coded so as to reflect the psychological phenomena of learning, forgetting and item effects (N = 50). The Index describes two rules for differentiating between cases of cognitive impairment and non-impairment. Rule 1 contrasts the respective contributions of learning and forgetting. Rule 2 takes account of cases characterized by a high proportion of correct responses. Against a criterion index based on performances on other psychological tests of organic dysfunction, the Waterford Index yielded higher predictive efficiencies than associated with other Wechsler indices, intelligence, and age.

Spatial perspective taking in young children

Four- and five-year-old children were tested in a spatial perspective task employing a production format. They were shown a photograph of an aspect of a doll house and asked to generate the view on the photograph for a puppet that served as the observer. The house was mounted on a lazy Susan and could be rotated freely by the children. Puppet line of regard (to a corner, side, or rear of the house) and photograph type (fron, corner, side, or rear) constituted within-subject factors. Puppet position, photograph type, and age affected patterns of errors and proportion of correct responses. It was concluded that perspective taking is highly task dependent as well as dependent upon developmental status.

Studies in observational paired-associate learning: Informational, social, and individual difference variables

Four experiments examined the relative importance of informational (proportion of correct responses and kinds of errors emitted by a model), social (model competency, sex of model, video vs. audio taped model), and individual difference (sex of subject, grade) variables in observational paired-associate learning. In Experiments I–III, vicarious subjects received cycles of study-model-test trials, while direct subjects were given the same sequences with intervening test or stimulus familiarization trials. In Experiment IV, vicarious subjects received cycles of study-test-model-test trials, while direct subjects received the cycles with a test trial replacing the model trial. No confirmation was provided on test and model trials. Whereas the effects attributable to social and individual difference variables were generally negligible, mere accuracy of the model's responses repeatedly covaried with performance on the last test trial of each cycle. Conditional analyses established that (1) vicarious facilitation is comparable across cycles and localized in items responded to incorrectly on immediately preceding test trials, and (2) observers learn fewer incorrect than correct model responses. Vicarious groups performed at reliably higher levels than direct subjects on model correct but not incorrect items. The results strongly suggest a close correspondence between direct and vicarious verbal learning principles and mechanisms.

Invariance of inference time when information was presented in different linguistic formats

Ss read paragraphs varying in syntactic complexity, contiguity of information that was conceptually related, and amount of information relating to quantitative variables. Paragraphs were presented too briefly to allow full reading in many cases. In questions requiring use of the quantitative information, proportion of correct responses was influenced by syntax, contiguity, and number of variables from the paragraph. However, neither syntax nor contiguity influenced latency of correct answers, while number of variables, a factor affecting complexity of the process of answering, did influence correct response latency. The findings confirm and extend earlier results by Kintsch and Monk (1972) and give further support to the proposition that assimilation of information in linguistic input involves storing the semantic content of the message.

STIMULUS CONTROL IN A TWO‐CHOICE DISCRIMINATION PROCEDURE1

The relation between performance during discriminative training and subsequently obtained measures of stimulus control was investigated. Pigeons served as experimental subjects. In the discriminative training phase, a single peck on the center key, transilluminated by a bright or dim white light, resulted in the onset of the side keys, one red and one green. If the center key was brightly lighted, a response on the red side key was correct. A response on the green side key was correct if the center key was dimly lighted. Correct responses were reinforced on independently arranged variable-interval schedules. Following discriminative training, tests of stimulus control were administered during which white light of 11 intensities was projected on the center key and responses on the red and green side keys recorded. The proportion of correct responses in the presence of a bright or dim center-key stimulus decreased with decreases in the frequency of reinforcement of correct red or correct green responses, respectively. The slopes of the stimulus control gradients were related to the extent of response bias during training. The greater the bias to respond on the green key, the flatter the gradient showing the proportion of green-key responses to each stimulus and the steeper the corresponding gradient of red-key responses.

Alcohol-State Dependent Learning: Acquisition of a Spatial Discrimination in the Goldfish (Carassius auratus)

Alcohol has been used to establish state-dependent learning (STDL). The present experiments found that the task of learning a spatial discrimination under the influence of alcohol was qualitatively different for goldfish than when alcohol was not present. Two 2 X 2 factorial designs with 4 Ss per cell were run. In both experiments it took more trials for fish trained and tested under different alcohol conditions to relearn the task; however, the proportion of correct responses for the acquisition phase remained stationary for alcohol-trained fish but gradually increased for water-trained fish. Alcohol-trained fish had a significantly faster mean time per response in the acquisition phase than did water trained fish. These findings suggest a more parsimonious interpretation of the STDL phenomenon in goldfish: What is learned is qualitatively different for alcohol and nonalcohol conditions.

Conceptual structure and conceptual tempo.

College students selected for extremes of concrete and abstract conceptual structure were given 4 visual information-processing tasks: Matching Familiar Figures, Design Recall test, Embedded-figures test, and a task requiring identification of familiar objects presented tachistoscopically at 1/100 sec. Schroder's theory of conceptual structure provided a basis for predicting that abstract Ss would proceed more reflectively on the tasks than would concrete Ss, i.e., abstract Ss were expected to show longer response times and a higher proportion of correct responses. Results showed little generality of either speed or accuracy over tasks, and no support for the conceptual structure hypothesis. Non-parametric analysis of over-all performance indicated that abstract Ss and males tended to be both faster and more accurate in visual tasks than concrete Ss and females, respectively.

Some Parameters Affecting the Differentiation of Modal-Falsetto Voice Quality

Previously [R. Colton and H. Hollien, J. Acoust. Soc. Amer. 47, 105(A), (1970)] it was reported that observers could distinguish modal and falsetto voice quality when the phonations from the two registers were presented at the same fundamental frequency and intensity. Other data [R. Colton, (unpublished)] demonstrates that modal phonations exhibit more energy in the higher harmonics than do falsetto phonations; suggesting that frequency bandwidth is an important cue for the differentiation of modal and falsetto voice quality. Phonations produced in the two vocal registers were low-pass filtered to equate the bandwidth of modal phonations to falsetto phonations. The filtered phonations were presented in a paired comparison paradigm to observers who judged the similarity or dissimilarity of voice quality of each stimulus pair. The proportion of correct responses was 0.71; a decrease of 20% when compared with the responses obtained for these phonations in an unfiltered condition. These results indicate that stimulus bandwidth is an important acoustic parameter for the differentiation of the modal and falsetto registers. However, an analysis of individual phonations suggest other acoustic differences may aid in the distinction of modal and falsetto voice quality.

Memory and the theory of signal detection.

A recurrent problem in the study of recognition memory has been that of combining hits and false alarms (or correct and incorrect responses) into a single index of performance. That the proportion of correct responses in a yes/no or multiple-choice recognition test may in some way be contaminated by factors other than the state of the memory system has never been seriously disputed, but only recently has the question received detailed and systematic attention. Traditionally the problem has been viewed in terms of correcting for chance success; in current terminology, and stated more generally, it is a problem of providing an adequate theory of the decision system which maps a given state of the memory system into an overt response. The reasons for this increased attention to decision processes in memory are not difficult to trace. In the first place, the development of quantitative theories of recognition memory has necessitated a precise and explicit account of how the memory and decision systems interact to produce a given response. If a theory of memory is to be tested against data from a recognition-me mory experiment, it is necessary to obtain performance measures that are independent of those parameters

Assessment of Mathematical Concepts of Five-Year-Old Children

An instrument, the Schwartz Early Mathematics Inventory (SEMI), was devised to assess, by means of group administration, the mathematical achievement of children ages 3 through 5. The data presented concern only the first stages of the process and deal only with 215 kindergartners. A reliability of . 94 was obtained on the eighty-one items administered on 64 pages. The mean for items correct 43. 2. The proportion of correct responses for various items ranged from . 85 to . 12. The children had satisfactorily acquired the physical and emotional attributes necessary for completing the inventory, namely, holding a pencil or crayon, turning pages, recording responses in designated areas, and maintaining satisfactory attention for the 12 to 28 minutes required for administering each of the three portions of the SEMI.

Deutsch's model applied to a conditional maze.

Rodents (mice) were rewarded for running over, but not for running under, an obstacle giving access to a final common path. On the basis of Deutsch's postulates it was predicted that the proportion of correct responses during test trials should depend upon the distribution of reinforcement during training trials; the proportion being high following block reinforcement, low following alternated reinforcement and intermediate in a procedure used by Sheldon. These predictions were upheld throughout testing in a maze with a long final path, but only held good for the early test trials in a shorter maze for which predictions are equivocal.