Effects of exact and category repetition in true and false recognition memory

Two experiments used the distinction between remembering and knowing to investigate the effects of exact and category repetition in recognition memory. In Experiment 1, exact repetition enhanced remember responses but had no reliable effect on know responses. In Experiment 2, category repetition enhanced correct know responses but had no effect on correct remember responses. Category repetition also increased false positive remember and know responses. It is argued that exact repetition influences the recollection component of recognition memory via the creation of multiple episodic traces, each of which is potentially capable of supporting a remember response, whereas category repetition influences the familiarity component of recognition memory by enhancing the fluency with which test items are processed.     

Comprehension of sentence structure in anomic and conduction aphasia

Picture-pointing auditory and reading comprehension tests were administered to anomic and conduction aphasics. Subjects responded to active sentences of the present progressive form. The possible errors which a subject could make on these experimental tasks included failure to correctly interpret noun order, number, or lexical meaning. Both groups made significantly more correct responses than error responses. Of their error responses, noun-order errors significantly exceeded number and lexical errors for which no differences were observed. When compared with results previously obtained for agrammatic Broca's aphasics, no differences in the pattern of errors were identified. These results are discussed relative to current theories of syntactic processing and for the mechanisms which account for these syntactic comprehension deficits following aphasia.     

On the likelihood ratio test in structural equation modeling when parameters are subject to boundary constraints

The authors show how the use of inequality constraints on parameters in structural equation models may affect the distribution of the likelihood ratio test. Inequality constraints are implicitly used in the testing of commonly applied structural equation models, such as the common factor model, the autoregressive model, and the latent growth curve model, although this is not commonly acknowledged. Such constraints are the result of the null hypothesis in which the parameter value or values are placed on the boundary of the parameter space. For instance, this occurs in testing whether the variance of a growth parameter is significantly different from 0. It is shown that in these cases, the asymptotic distribution of the chi-square difference cannot be treated as that of a central chi-square-distributed random variable with degrees of freedom equal to the number of constraints. The correct distribution for testing 1 or a few parameters at a time is inferred for the 3 structural equation models mentioned above. Subsequently, the authors describe and illustrate the steps that one should take to obtain this distribution. An important message is that using the correct distribution may lead to appreciably greater statistical power.     

Effects of regular switching between languages during random number generation

Random number generation is a task that engages working memory and executive processes within the domain of number representation. In the present study we address the role of language in number processing by switching languages during random number generation (numbers 1-9), using German (L1) and English (L2), and alternating L1/L2. Results indicate large correspondence between performance in L1 and L2. In contrast to nonswitching performance, randomization with alternating languages showed a significant increase of omitted responses, whereas the random sequences were less stereotyped, showing significantly less repetition avoidance and cycling behavior. During an intentional switch between languages, errors in language sequence appeared in 23% of responses on the average, independently of the quality of randomization but associated with a clear persistence of L2. These results indicate that random number generation is more closely linked to auditory-phonological representation of numerals than to visual arabic notation.     

Diagnosing and Caring for the Reading Difficulties of College Freshmen

One hundred forty-four subjects dichotomized as internal or external on the I-E scale were randomly assigned to one of three reinforcement conditions-no reinforcement, self-reinforcement, or external reinforcement-and one of three subject determination of the correct response conditions-0%, 50%, or 100%. Trials to criterion and errors to criterion on a complex verbal discrimination task were the dependent variables. The results demonstrated that self-reinforcement influenced learning to a greater degree than no reinforcement. Further, when subjects were allowed to determine 100% of the correct responses, the effects of self-reinforcement paralleled the effects of external reinforcement. When subjects determined 50% or 0% of the correct responses, the self-reinforcement and no reinforcement conditions did not differ in influencing overall rate of learning. Internals made significantly fewer errors than externals.     

Shock as punishment in a picture-naming task with retarded children

Two retarded children were taught to name pictures according to a standardized procedure. In Exp. I, correct responses were positively reinforced on a five to one ratio under one stimulus condition, incorrect responses were followed with a sharp "no", and the subject was ignored for inattentive behavior. Under another stimulus condition, correct responses were reinforced as in the first condition, but incorrect responses and 5-sec periods of inattentive behavior were followed by "no" and an electric shock. Less inattentive behavior was exhibited and more words were learned to a pre-set criterion in the shock condition than in the no-shock condition. In Exp. II, the ratio of inappropriate responses to shock was varied. The amount of inattentive behavior tended to increase in the shock condition, relative to that in the no-shock condition, as this ratio was increased. Two other measures of performance used in the present experiments were the ratio of errors to correct responses and the number of correct responses. Shock tended to produce better performance on these measures also.     

Application of a model to paired-associate learning

The proposal is made to consider a paired-associate item as becoming conditioned to its correct response in all-or-none fashion, and that prior to this conditioning event the subject guesses responses at random to an unlearned item. These simple assumptions enable the derivation of an extensive number of predictions about paired-associate learning. The predictions compare very favorably with the results of an experiment discussed below.This research was supported by a grant, M-3849, from the National Institutes of Mental Health, United States Public Health Service.     

Exploring the false recognition of category exemplars: Effects of divided attention and explicit generation

Two experiments used the category repetition procedure (Dewhurst & Anderson, 1999) to test the hypothesis that false remember (R) responses occur because participants generate associates to items presented at study. Participants in Experiment 1 studied the categorised lists either with full attention or whilst performing one of two secondary tasks (articulatory suppression or random number generation). Both secondary tasks led to a reduction in the number of false R responses, with random number generation producing the greater effect. Experiment 2 manipulated the presentation duration of study items and the instructions given to participants. The numbers of false R responses were not influenced by presentation duration, but increased when participants were explicitly instructed to make associations to study items. The findings support the view that false R responses are caused by the activation of semantic associates at encoding.     

Stimulus-naming effects at different stages of motor paired-associate learning

In a combined verbal and motor paired-associate task, nonsense names and button-pushing responses were learned for three random shapes, with verbal training beginning after 3, 12, or 24 motor learning trials. Earlier studies indicated that concurrent verbal and motor learning produce a strong tendency for the naming and button-pushing responses to be learned in “consistent” pairs. According to the theoretical analysis presented, the verbal-motor consistency is explained by the development of name-button associations. It was predicted that these associations affect both motor errors and correct responses, that their effects are greater for correct responses, and that attenuation of the effects due to delay in verbal training is gr, eater for motor errors. The results are in good agreement with the predictions, and they suggest that name-button associations develop rapidly even under delayed verbal training.     

Pictorial perspective: perception of size, linear, and texture perspective in children and adults

Perception of size, linear, and texture perspective was investigated in third-grade and sixth-grade children and in college adults in three separate studies. A matching task required the observer to choose from a set of four alternative real scenes the correct match for the test stimulus, which was either a picture or a real scene. Correct performance required that the subject utilize perspective information for both size and distance distance relations. Erroneous choices available to the subject indicated errors in size judgement, in distance judgment, or in both simultaneously. View was either restricted at the correct station point or was free, with head motion. There were no significant effects of grade level. For all three groups, mean percent correct was nearly 100% with the real-scene test stimuli, and significantly below the chance level with the picture test stimuli. Errors in size judgment occurred most frequently, indicating that the geometrically correct rate of perspective convergence was too rapid to be seen by the subjects as perceptually acceptable. With size-perspective information alone, the number of size plus distance errors also increased significantly. There was no significant effect of viewing condition.     

Rank‐based permutation approaches for non‐parametric factorial designs

Inference methods for null hypotheses formulated in terms of distribution functions in general non‐parametric factorial designs are studied. The methods can be applied to continuous, ordinal or even ordered categorical data in a unified way, and are based only on ranks. In this set‐up Wald‐type statistics and ANOVA‐type statistics are the current state of the art. The first method is asymptotically exact but a rather liberal statistical testing procedure for small to moderate sample size, while the latter is only an approximation which does not possess the correct asymptotic α level under the null. To bridge these gaps, a novel permutation approach is proposed which can be seen as a flexible generalization of the Kruskal–Wallis test to all kinds of factorial designs with independent observations. It is proven that the permutation principle is asymptotically correct while keeping its finite exactness property when data are exchangeable. The results of extensive simulation studies foster these theoretical findings. A real data set exemplifies its applicability.     

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.     

Repetition in the transcortical aphasias

Transcortical aphasic patients were assessed on a repetition task comprised of both well-formed and deviant sentences. The patients faithfully repeated those sentences that were factually incorrect but grammatically well formed, and those sentences that were ungrammatical because of selection restriction violations. In contrast, presented with sentences featuring only minor syntactic violations (e.g., lack of number agreement), the patients spontaneously, and without awareness, resisted exact repetition; moreover, the resultant changes most often served to correct the syntactic deviations. Repetitions of sentences of this latter type also revealed a difference between the patients as a function of level of comprehension. The transcortical motor aphasic patient was influenced by semantic factors in his alterations of the minor syntactic violations, while the transcortical sensory aphasic was not. These findings are discussed in relation to the notion of autonomous syntactic processing. They are taken to suggest that syntactic facts such as number agreement are represented at a level in the processing chain that is distinct from that of semantic representation.     

Dissociation of data-based and expectancy-based memory following hippocampal lesions in rats

Sham-operated and nonoperated animals or animals with hippocampal lesions were presented with sets of trials to test both expectancy-based and data-based memory within the same task. During the study phase of each trial the animals were presented with a constant sequence of five arms on an eight-arm radial maze followed by a test phase in which a recognition test requiring a win-stay rule was used. Expectancy-based memory was measured during the study phase of the trials as a pattern of correct or incorrect orienting responses in anticipation of the ensuing doors in the constant sequence. Both groups of animals acquired correct orienting responses at the same rate, emitted the same pattern of correct orienting responses, and made the same number and pattern of intralist and extralist intrusion errors. Data-based memory was measured during the test phase of the trial as correct recognition test performance. During the test phase the animals with hippocampal lesions were impaired relative to controls on both immediate and 24-h recognition tests. These results suggest that the hippocampus might mediate only data-based, but not expectancy-based, memory and imply a possible dissociation between expectancy-based and data-based memory systems.     

Optimal response biases and the slope of ROC curves as a function of signal intensity,signal probability,and relative payoff

Rats performed in a two-lever analogue of the yes-no psychophysical procedure. The signal consisted of of an increment in the intensity of a random noise. Correct responses were reinforced with single bursts of brain stimulation; incorrect responses produced brief periods of time-out. Receiver-operating-characteristic curves were generated at each of several signal intensities by varying either the signal probability (0.1–0.9) or the relative number of brain stimulations for correct responses (1:3–3:1). The index d’ (or d’_e) increased with the signal intensity and was independent of response bias. When the signal probability was varied, the animals optimized the number of correct trials. and hence the number of brain stimulations obtained at each level of detection. They approximated this optimum more closely as the signal intensity was reduced. When the ratio of brain stimulations was varied, the animals compromised between optimizing the number of correct trials and optimizing the number of brain stimulations obtained. The slopes of the ROC curves plotted on normal-normal coordinates frequently departed from unity, but did not change systematically with either the signal intensity or the method by which they were generated.     

Response time distributional evidence for distinct varieties of number attraction

Speakers are known to make subject–verb agreement errors both when a number-mismatching noun intervenes between the head of the subject phrase and the verb (e.g., ¹The key to the cabinets are on the table) and in configurations in which there is a number-mismatching noun that does not intervene (e.g., ¹The cabinets that the key open are on the second floor). Using a two-choice response time (RT) paradigm, Staub (2009) found that correct agreement decisions were also slowed in both cases. The present article reports a new experiment designed to explore whether these two RT effects are qualitatively similar or different. Fitting of the ex-Gaussian distribution (Ratcliff, 1979) to individual subjects’ RT data, in each condition, demonstrated that the effect of an intervening number attractor on correct RT is due to both a shifting of the distribution to the right and to increased skewing, while the effect of a non-intervening attractor is almost entirely a skewing effect. A non-parametric vincentizing procedure supported these conclusions. These findings are taken to support the view that these two types of number attraction involve distinct processing mechanisms.     

Wholistic and analytic stimulus processing: The development of selective perceptual strategies

This experiment reports an investigation of the development of selective processing strategies as subjects become increasingly more practised at a serial self-paced RT task. It demonstrates the effect a preceding stimulus can have on the analysis of a current signal and the development of active analytic strategies in favour of passive wholistic processing, with practice. The stimuli used were letters with irrelevant visual noise dot patterns superimposed on them. The letter, or the dot pattern, or both, could be repeated on successive trials. Early in practice repetition of both stimulus components simultaneously produced short reponse latencies relative to repetition of the letter alone. The number of noise dots markedly affected RT. Late in practice, however, letter repetition RTs were small, irrespective of whether or not the noise dot pattern was repeated. Furthermore, the number of noise dots no longer had an effect on the RT to these stimulus transitions. The results suggest that subjects appear to be able to select relevant information to process as they become progressively more practised, even though there is evidence that they compare the current stimulus with an iconic representation of the immediately preceding one.     

Chlorpromazine and serial reaction performance

The effect of 25 mg or 75 mg of chlorpromazine on the serial reaction performance of 12 male human subjects was studied. Speed or number of correct responses was reduced by the high dose of chlorpromazine and errors of commission and omission were increased. The adverse effect of the drug upon speed appeared only at the end of the half-hour test. By contrast the adverse effect upon gaps and errors was apparent throughout the test and there was no interaction with test duration.     

Bias functions and operating characteristics of rats discriminating auditory stimuli

Rats were trained to discriminate between two bursts of random noise that differed in intensity. In a two-lever, discrete-trial procedure, correct responses were reinforced with brain stimulation, and incorrect responses produced timeout. Responding was studied as a function of the decibel difference between the stimuli, the probabilities of presenting the stimuli, the relative duration of timeout consequent upon the two types of incorrect responses, and the absolute duration of timeout consequent upon incorrect responses. The results showed that the distribution of responses between the two levers depended upon the stimulus probabilities, but were independent of either the absolute or relative durations of timeout. When the stimulus probabilities were varied, the response probabilities did not match the stimulus probabilities; when the relative durations of timeout were varied, the animals did not obtain the maximum rate of reinforcement per unit time. Instead, the animals distributed their responses so as to obtain the maximum number of reinforcements at each level of discrimination. In addition, the level of discrimination increased as a function of the decibel difference between the stimuli.     

Transcortical sensory aphasia: Evidence for subtypes

Impaired auditory comprehension and fluent but semantically empty speech in conjunction with preserved repetition characterize the syndrome of transcortical sensory aphasia (TSA). Repetition, however, may be mediated by at least two distinct processes--a lexical process that may involve the recognition and subsequent activation of discrete stored word representations and a nonlexical process that involves phonologic decoding and immediate phonologic encoding from immediate memory. We investigated the spontaneous speech, reading, and tendency to recognize and spontaneously correct syntactic errors in four patients with TSA: this analysis suggests there are two subtypes of TSA. We contend that in one subtype both the lexical and direct repetition (or speech production) mechanisms are preserved, but in the second subtype the lexical mechanism is disrupted and repetition is mediated by the nonlexical mechanism.