Increased semantic and repetition priming in schizophrenic patients

Positive and negative priming (PP and NP) in schizophrenia were studied with a lexical-decision task. Probe words, presented 800 ms after the response to the prime (containing a word and a nonword), were either identical to, semantically related to, or unrelated to the prime target word (PP) or to the prime distractor word (NP). Schizophrenic patients displayed stronger semantic and repetition PP than controls after controlling for their slower responses. Significant NP was observed in both groups for word repetition only. The PP findings contrast with results from studies with similar prime-probe intervals but without prime responses. It is proposed that schizophrenic patients, because of impaired (controlled) processes of response selection, strongly benefit from (or rely on) the automatic retrieval of processing episodes containing response information. Related findings indicating automatic response facilitation in schizophrenia are discussed.     

Management of chronic psychiatric patients by a token reinforcement system

A token reinforcement system for the reduction of institutionalized behavior in a chronic psychiatric ward is described. Quantitative assessments were made of the effects of the system on five types of positively reinforced behavior, two types of unreinforced behavior, and two types of fined behavior. To assess whether these effects were a function of the token procedures, three experiments were carried out, the first removing tokens for a brief period, the second making tokens non-contingent on behavior, and the third removing fines in one area while maintaining them in another. The token procedures were found to be the source of the observed improvements.     

Visuospatial priming of the mental number line

It has been argued that numbers are spatially organized along a "mental number line" that facilitates left-hand responses to small numbers, and right-hand responses to large numbers. We hypothesized that whenever the representations of visual and numerical space are concurrently activated, interactions can occur between them, before response selection. A spatial prime is processed faster than a numerical target, and consistent with our hypothesis, we found that such a spatial prime affects non-spatial, verbal responses more when the prime follows a numerical target (backward priming) then when it precedes it (forward priming). This finding emerged both in a number-comparison and a parity judgment task, and cannot be ascribed to a "Spatial-Numerical Association of Response Codes" (SNARC). Contrary to some earlier claims, we therefore conclude that visuospatial-numerical interactions do occur, even before response selection.     

Modification of interactive behaviors in chronic mental patients

Four chronic mental patients, residents of a token economy treatment unit, were randomly assigned to an experimental or control condition and attended 10 thirty-minute treatment sessions. For the two experimental subjects, contingent reinforcement was received for interacting with each other according to instructions in four distinct phases of interpersonal behavior: talking to another person, attending and talking to another person, asking and answering questions in a dyad, and working cooperatively in the dyad to solve problems. The two control subjects were instructed to perform the same behaviors but received non-contingent reinforcement. The results indicated a strong contingent reinforcement effect on the performance of the treatment sessions' target behaviors. Several baseline, treatment, and post-treatment response measures indicated that the treatment effects had generalized to other areas of social behavior away from the treatment setting.     

Behavioral contrast and response independent reinforcement

Four pigeons received pre-training that included presentation of the reinforcer independently of behavior and then baseline training on a variable-interval schedule of reinforcement. With the introduction of a multiple schedule, in which the first stimulus was associated with a response contingent and a second stimulus with a response independent, 1-min variable-interval schedule, a reduction in response rate was obtained in the second component, which was not accompanied by a behavioral contrast effect in the first component. A further three pigeons were given the same pre-training and baseline training before the introduction of an otherwise identical multiple schedule, in which no reinforcement occured in the second component. Behavioral contrast was obtained from all three subjects. The results indicated that under conditions of constant reinforcement density a reduction in responding is not a sufficient condition for the occurrence of behavioral contrast.     

Perceptual and response interactions in semantic priming

In two experiments, subjects made pairs of lexical decisions verbally. In Experiment 1, masked stimuli appeared concurrently to the left and right of fixation; in Experiment 2, nonmasked stimuli appeared sequentially at fixation. The left-hand letter strings were judged more accurately in in Experiment 1, and the second letter strings were judged more accurately in Experiment 2. Each string in the pair could be either a word (e.g., fork) or a nonword anagram (e.g., frok). Consequently, the two strings in the pair could be related (e.g., fork-spoon, frok-spoon, etc.) or unrelated (e.g., fork-door, frok-door, etc.), independently of whether neither, either, or both strings were words. Semantically related stimuli induced consistent biases to respond "word," as noted in other studies. These biases were typically stronger for the event reported second. Minimal evidence was found for perceptual priming effects. The asymmetrical effects were consistent with spreading-activation-type mechanisms, but other considerations support a multiple-process view.     

Attack produced by intermittent reinforcement of a concurrent operant response

Squirrel monkeys pressed a lever to produce food on several fixed-ratio schedules; they could also bite a rubber hose. Biting attack occurred during the postreinforcement pause and in early portions of the ratio response run. Also, biting attacks increased after transitions to higher values of the fixed-ratio requirement and in extinction. The results show that extinction-induced aggression effects occur in primates.     

Syntactic priming: Investigating the mental representation of language

We argue that psycholinguistics should be concerned with both the representation and the processing of language. Recent experimental work on syntax in language comprehension has largely concentrated on the way in which language is processed, and has assumed that theoretical linguistics serves to determine the representation of language. In contrast, we advocate experimental work on the mental representation of grammatical knowledge, and argue that sybtactic priming is a promising way to do this. Syntactic priming is the phenomenon whereby exposure to a sentence with a particular syntactic construction can affect the subsequent processing of an otherwise unrelated sentence with the same (or, perhaps, related) structure, for reasons of that structure. We assess evidence for syntactic priming in corpora, and then consider experimental evidence for priming in production and comprehension, and for bidirectional priming between comprehension and production. This in particular strongly suggests that priming is tapping into linguistic knowledge itself, and is not just facilitating particular processes. The final section discusses the importance of priming evidence for any account of language construed as the mental representation of human linguistic capacities.The order of the first two authors is arbitrary. H.B. is supported by an EPSRC Postgraduate Studentship. M.P. is supported by a British Academy Postdoctoral Felowship. S.L. is supported by a University of Nottingham Postdoctoral Fellowship. A.S. was supported by British Academy Research Grant awarded to M.P. T.U. is in part supported by a Mellon Science Development Grant. We would like to thank Dave Elmes, Tyler Lorig, Matt Traxler, an anonymous reviewer, and members of the Sentence Processing Group, Human Communication Research Centre, Universities of Edinburgh and Glasgow.     

Task difficulty and response complexity modulate affective priming by emotional facial expressions

In this study we used an affective priming task to address the issue of whether the processing of emotional facial expressions occurs automatically independent of attention or attentional resources. Participants had to attend to the emotion expression of the prime face, or to a nonemotional feature of the prime face, the glasses. When participants attended to glasses (emotion unattended), they had to report whether the face wore glasses or not (the glasses easy condition) or whether the glasses were rounded or squared (the shape difficult condition). Affective priming, measured on valence decisions on target words, was mainly defined as interference from incongruent rather than facilitation from congruent trials. Significant priming effects were observed just in the emotion and glasses tasks but not in the shape task. When the key–response mapping increased in complexity, taxing working memory load, affective priming effects were reduced equally for the three types of tasks. Thus, attentional load and working memory load affected additively to the observed reduction in affective priming. These results cast some doubts on the automaticity of processing emotional facial expressions.     

Service planning for chronic mental patients: some principles

Services for chronic mental patients in this era of deinstitutionalization present a major challenge to clinicians and planners alike. The complexity of these patients' clinical and other programmatic needs requires that an array of viable comprehensive services be made available to them. Following certain established principles of service planning will help facilitate patients' longitudinal, psychological, financial, and geographical access to care.     

The treatment of a chronic obsessive condition via reinforcement contingent upon success in response prevention

The patient, who exhibited multiple, long-standing, obsessive ritualistic behaviour was being considered for psychosurgery. The two major rituals were a counting and wiping ritual during defecation and an excessive pre-occupation with electrical equipment. The treatment involved an incomplete reversal design using response-prevention motivated by reinforcement withdrawal. Baseline rates of his checking and ritualistic behaviour were obtained in hospital over a 5-day period, while the patient's wife obtained similar baseline data over the first weekend at home. Following the baseline period, the patient was informed that in order to obtain his daily and weekend reinforcement, he must significantly decrease ritualistic activities, while increasing social and other incompatible behaviour. After the third week of treatment the patient's checking behaviour had ceased and his washing, dressing and toilet behaviour were within normal limits. His weekend behaviour followed a similar pattern, and he returned to full-time employment by the seventh week. The 6-month follow-up indicated a further increase in incompatible behaviour, in addition to the maintenance of his success in response prevention. Relapse was probably obviated by the use of concurrent home and hospital treatment.     

Intermittent reinforcement of a continuous response

Konorski showed that when a go/no-go procedure was used, sound quality discriminations were rapidly acquired and sound location discriminations were slowly acquired. These findings have been interpreted as a general constraint on the acquisition of auditory discriminations (quality-location effect). However, experiments carried out within an evolutionary framework (Harrison, 1984) have shown that the rate of acquisition of sound location discriminations varies widely as a function of the inclusion or exclusion of naturalistic features. These data suggest that Konorski's findings were a function of the special conditions of the experiments. The first purpose of the present experiments was to assess whether rats showed the effects noted by Konorski when studied under similar conditions. The second purpose was to study the effect of manipulating two natural features (novelty and stimulus-response adjacency) to assess whether the acquisition rates of quality and location discriminations could be greatly modified or made approximately equal, or both. When a go/no-go procedure was used and the other conditions were similar to those of Konorski, rats acquired a quality discrimination but did not acquire a location discrimination. However, when the S+ or S- were presented through a closely adjacent speaker, the sound location discrimination was acquired as rapidly as the quality discrimination. Finally, preexposing the animal to either S+ or S- retarded the rate of or prevented the acquisition of the quality discrimination. The experiments showed that the quality-location effect was determined primarily by the conditions used in Konorski's experiments, and that the effect is not a general constraint on learning.     

Concurrent performances: inhibition of one response by reinforcement of another

In an analysis of interactions between concurrent performances, variable-interval reinforcement was scheduled, in various sequences, for both keys, for only one key, or for neither key of a two-key pigeon chamber. With changeover delays of 0.5 or 1.0 sec, and with each key's reinforcements discriminated on the basis of key-correlated feeder stimuli, reinforcement of pecks on one key reduced the pecking maintained by reinforcement on the other key. The decrease in pecking early after reinforcement was discontinued on one key was not substantially affected by whether pecks on the other key were reinforced, but after reinforcement was discontinued on both keys, reinstatement of reinforcement for one key sometimes produced transient increases in pecking on the other key. Correlating the availability of right-key reinforcements with a stimulus, which maintained right-key reinforcement while reducing right-key pecking to negligible levels, demonstrated that these interactions depended on concurrent reinforcement, not concurrent responding. Thus, reinforcement of a response, but not necessarily the occurrence of the response, inhibits other reinforced responses. Compared with accounts in terms of excitatory effects of extinction, often invoked in treatments of behavioral contrast, this inhibitory account has the advantage of dealing only with observed dimensions of behavior.     

Punishment of an extinguishing shock-avoidance response by time-out from positive reinforcement

Two experiments were conducted to determine the effects of punishment by time-out from positive reinforcement on the extinction of discriminated shock-avoidance responding. Subjects were trained initially to bar press for food on an intermittent schedule of reinforcement and, concurrently, to avoid shock at the onset of a warning signal. Experiment I compared avoidance extinction performance under no punishment and when avoidance responding resulted in a 30-sec TO from reinforced appetitive responding. In Exp II, the contingent use of TO punishment was compared with its random, or noncontingent use. The results of both experiments showed that in the absence of punishment, avoidance extinction was characterized by short latencies and nearly 100% avoidance responding. Avoidance responding in extinction was little affected by noncontingent TO punishment. When TO was made contingent upon avoidance responding, however, avoidance latencies immediately increased and the frequency of avoidance responses subsequently decreased to zero.     

The effects of reinforcement on the modification, maintenance, and generalization of social responses of mental patients

Social greeting responses of three withdrawn, chronic schizophrenics were experimentally modified. Initially, none of the subjects spoke to an experimenter. Prompts and cigarette reinforcement were employed to produce increases in the rates of greetings. Then, the prompts were faded so that the greetings came under the control of the presence of the experimenter. Reversal and subsequent reinforcement procedures were employed to demonstrate that the responses were controlled by their consequences. Next, the schedule of cigarette reinforcement was leaned out so that greetings continued to occur in the absence of cigarette reinforcement. However, low or zero rates of greetings occurred in the presence of a second experimenter. Five new experimenters employed the prompting, fading, reinforcement, and schedule-leaning procedures. Subsequently, all subjects emitted appropriately high rates of greetings in the presence of the second experimenter. Without further application of the experimental procedures, greetings were still occurring in the presence of both the first and second experimenters almost three months later.