Conscious and unconscious lexical retrieval blocking in younger and older adults

The effects of orthographically overlapping prime words in a word fragment completion task (modified from S. M. Smith & D. R. Tindell, 1997) were studied in younger and older adults. Participants studied words and then completed word fragments corresponding to those words. Fragments were preceded by a blocking, unrelated, or neutral prime. In Experiment 1, all participants were slower and less likely to complete the word fragments correctly in the blocking prime condition. Older adults also were more likely to use the blocking prime to incorrectly complete the word fragment compared with younger adults, even when warned against doing so (Experiment 2). Experiment 3 used a masked priming paradigm in younger adults to examine whether conscious processing of the prime word was necessary to produce blocking effects. Reliable blocking effects were obtained, including an intrusion rate similar to that observed in older adults in the first two experiments. These results suggest that certain aspects of word-finding failures in normal aging may be related to the reduced ability to control the activation of a lexical competitor when attempting to retrieve a target word.     

The Role for Occupational Therapists in Community Mobility Training for People With Autism Spectrum Disorders

Symptoms and behaviors of Autism Spectrum Disorders can challenge community mobility, thus hindering independence and participation in occupation. Community mobility, also called travel training, helps people make journeys safely using public transportation, enabling engagement in activities/services otherwise unavailable. Yet, few articles have been written about this topic for people with Autism Spectrum Disorders. The purpose of the authors in this article is to: (1) explain the need for travel training with people diagnosed with Autism Spectrum Disorders; (2) describe specific travel training assessments; (3) review literature on travel training programs; and (4) define a role for occupational therapy in travel training with individuals diagnosed with Autism Spectrum Disorders.     

Commentary on Paper by Ellen F. Fries

In Perchance to Sleep: Minding the Unworded Body in Psychoanalysis, Ellen F. Fries masterfully articulates the complexities of right-brain to right-brain, body-to-body interactions between herself and her patient. Her work highlights the dominance of the nonverbal implicit self over the verbal, explicit self and provides an excellent example of clinical work in which she thoughtfully attends to the unspoken, bodily based communication that takes place within the therapeutic dyad. In this discussion, I offer perspectives from Sensorimotor Psychotherapy on the impact of early attachment on the procedural organization of action sequences that reflect and sustain the implicit self, and embody unconscious relational expectations. The following topics are addressed: (a) Physical actions that provide avenues of exploration into the implicit self, especially actions such as reaching out, making eye contact, or maintaining an upright posture that are abandoned or distorted when they are ineffective in eliciting the desired response from attachment figures; (b) Body-oriented interventions that target the involuntary physical spasms that Fries' patient experiences, which are associated with unresolved physiological arousal originally stimulated in the face of trauma; and (c) The nonverbal manifestation and negotiation of enactments that emerge from the body-to-body dialogue between the implicit selves of patient and therapist.     

Is there a search in fixed-set memory search?

We discuss the hypothesis that structural factors in the fixed-set memory-search task may contribute to the standard linear set-size effect typically observed in this task. We constructed a lexical decision task that contained the same structural factors as the memory-search task. Two structural factors are discussed: (1) the priming of the probe by the memory set, and (2) the confounding of repetitions per item with set size. Our experiment demonstrated that these structural factors play a role in the set-size effect. The implications of these effects for the memory-search task and for models proposed to account for memory-search data are discussed.     

Rule-based and exemplar-based classification in artificial grammar learning

In this study, we examined the induction of syntactic rules, given the presentation of letter strings generated from a finite-state grammar. Our primary interest was whether application of abstracted syntax or analogy to remembered exemplars could serve as a basis for judgments of grammaticality of novel stimuli. The grammatical status of test items and their objective similarity to studied exemplars were manipulated independently to investigate whether rule-based or instance-based information was a more important determinant of classification performance. When group data were examined, the results indicated that both factors were equally important in influencing grammaticality judgments about novel letter strings. There were, however, large individual differences in the magnitude of grammatical status effects, with a subgroup of subjects clearly using a classification strategy other than analogy to remembered exemplars. The results offer qualified support for the hypothesis (Reber & Allen, 1978) that rule-based information can be implicitly abstracted given limited experience with richly structured stimulus domains, and these results are inconsistent with a strong version of the instance-based model of categorization.     

Perception of synthetic speech produced automatically by rule: Intelligibility of eight text-to-speech systems

We present the results of studies designed to measure the segmental intelligibility of eight text-to-speech systems and a natural speech control, using the Modified Rhyme Test (MRT). Results indicated that the voices tested could be grouped into four categories: natural speech, high-quality synthetic speech, moderate-quality synthetic speech, and low-quality synthetic speech. The overall performance of the best synthesis system, DECtalk-Paul, was equivalent to natural speech only in terms of performance on initial consonants. The findings are discussed in terms of recent work investigating the perception of synthetic speech under more severe conditions. Suggestions for future research on improving the quality of synthetic speech are also considered.     

In search of the point of no return: the control of response processes

Control processes underlying response inhibition were examined. Six Ss performed a visual choice reaction task and were occasionally presented with a tone that told them to withhold the response. Reaction time results were in agreement with a model that assumes a race between response activation and response inhibition processes. Event-related brain potentials, electromyogram, and continuous response measures showed that responses could be interrupted at any time. Evidence was obtained for two inhibitory mechanisms: inhibition of central activation processes and inhibition of transmission of motor commands from central to peripheral structures. Results have implications for the distinction between controlled and ballistic processes.     

Attaining and maintaining preparation: A comparison of attention in hyperactive,normal, and disturbed control children

The hypothesis that hyperactive children have a deficit in sustained attention was investigated. Eighteen children who had attention deficit disorder with hyperactivity (ADDH), aged 7 to 11 years, were compared with children who had conduct disorder (n = 15), mixed conduct disorder and ADDH (n = 26), emotional disorder (n = 18), or learning disability (n = 22), and with normal controls (n = 15). The subjects were tested on three versions of the Continuous Performance Task. Sustained attention was assessed from performance with increasing time on task and from ability to prepare attention in response to a warning. Performance of all subjects deteriorated with increasing time and improved with the opportunity to prepare attention. Hyperactive subjects were not more adversely affected by increasing time, nor did they benefit less than controls from the opportunity to prepare attention. Data reanalysis after rediagnosis according to ICD-9 criteria did not change the results. This study did not confirm the hypothesis that hyperactive children have a unique sustained attention deficit.     

Assessing teaching opportunities in a residential treatment facility

Seventeen living units in a residential treatment facility for developmentally disabled persons were assessed to determine the availability of teaching opportunities during the course of a normal day's routine. Teaching opportunities exist when the environment is arranged so that residents can participate in the ongoing activities. The teaching opportunities are identified within components that are recognizable activities that occur routinely and have a functional purpose. An assessment form was constructed as a means for documenting teachng opportunities. Assessments were conducted continuously from early morning through evening activities. The results of the assessments suggested that two approaches to resident care were in operation at the facility: one was characterized by a traditional care/custodial model, the other was characterized by a teaching model. On units where the number of teaching opportunities available was high, there was a smaller percentage of unstructured time, i.e., blocks of time when opportunities to engage in structured activities were not available to the residents.