Autonoetic awareness associated with the projection of the self into the future: an investigation in schizophrenia.

Autonoetic awareness associated with the projection of the self into the future was assessed in patients with schizophrenia using an experiential approach. Patients anticipated fewer specific future events than controls, and their ability to pre-experience future events was impaired, indicating that autonoetic awareness for the future is impaired in schizophrenia.

Temporal context memory in high-functioning autism.

Episodic memory, i.e. memory for specific episodes situated in space and time, seems impaired in individuals with autism. According to weak central coherence theory, individuals with autism have general difficulty connecting contextual and item information which then impairs their capacity to memorize information in context. This study investigated temporal context memory for visual information in individuals with autism. Eighteen adolescents and adults with high-functioning autism (HFA) or Asperger syndrome (AS) and age- and IQ-matched typically developing participants were tested using a recency judgement task. The performance of the autistic group did not differ from that of the control group, nor did the performance between the AS and HFA groups. We conclude that autism in high-functioning individuals does not impair temporal context memory as assessed on this task. We suggest that individuals with autism are as efficient on this task as typically developing subjects because contextual memory performance here involves more automatic than organizational processing.

Inhibition of inappropriate responses is preserved in the Think-No-Think and impaired in the random number generation tasks in schizophrenia.

We examined the ability of 23 schizophrenia patients and 24 healthy controls to exert intentional inhibition of prepotent responses in the Think-No-Think (TNT) paired-associate learning paradigm (Anderson & Green, 2001). TNT manipulates the frequency (1, 8, 16 times) of intentional attempts to suppress (inhibit) some target words and to respond to most cue words. Following a TNT practice-phase, recall of suppressed words was tested in two ways, using the same cue words initially learned, and the category name plus letter-stem of the target words. Inhibition of prepotent responses was also examined in a random number generation (RNG) task. In TNT, speed results showed longer reaction times after 16 suppress attempts in patients, not in controls, reflecting increased difficulty with retrieving the memory traces of the overridden items. In accuracy, no between-groups differences were evidenced, and overall patterns replicated those of Anderson & Green. In RNG, patients produced more stereotyped responses and ascending and descending counting than controls, pointing to on-line failures to inhibit prepotent responses. These findings suggest that schizophrenia patients' difficulties to inhibit prepotent responses appear specific, not widespread, the intentional inhibition addressed in TNT being preserved, and on-line inhibition in RNG being impaired.

Differential disruptions of working memory components in schizophrenia in an object-location binding task using the suppression paradigm.

Patients with schizophrenia exhibit normal memory for separate objects or locations but are disproportionately impaired when the items must be bound for later recognition in a working memory (WM) setting (Burglen et al., 2004). This study aimed at further evaluating the contribution of each WM component to the patients' binding deficit, using selective articulatory, visuospatial, and executive suppression tasks. In the object-location binding task used, a trial comprised the successive presentation of three drawings of familiar objects and of three spatial locations in a grid, either separately (i.e., objects alone or locations alone) or bound (i.e., object+location), and required a recognition test following an 8-s delay. In the suppression modalities, suppression was continuous from presentation to test. A total of 22 patients with schizophrenia and 24 healthy controls participated. The results confirmed the binding deficit in patients' performance in the baseline modality where no suppression was required. They also showed that patients were particularly disrupted when suppression was visuospatial. This last finding extends the specific visuospatial vulnerability in schizophrenia to the operations of binding.

Impaired performance in a working memory binding task in patients with schizophrenia.

This study investigated feature binding in a working memory task in patients with schizophrenia and in normal controls. Twenty-five patients and 25 controls participated. On each trial, three drawings of familiar objects were presented sequentially, each in a different cell of a 3 x 3 grid. In different blocks of trials, participants remembered either individual features (object and location conditions) or an object and its location (combination condition). The results showed that patients were slower and less accurate than controls under all conditions. Accuracy of both groups was reduced in the combination condition relative to the single-feature conditions, but patients showed disproportionately poorer performance in the combination condition than in the object and location conditions. Thus, patients with schizophrenia exhibit deficits in working memory, particularly when the task requires binding objects to their locations. This finding demonstrates that processes that establish coherent and temporary episodic representations in working memory are impaired in schizophrenia.

Impaired strategic regulation of contents of conscious awareness in schizophrenia.

Conscious awareness comprises two distinct states, autonoetic and noetic awareness. Schizophrenia impairs autonoetic, but not noetic, awareness. We investigated the strategic regulation of relevant and irrelevant contents of conscious awareness in schizophrenia using a directed forgetting paradigm. Twenty-one patients with schizophrenia and 21 normal controls were presented with words and told to learn some of them and forget others. In a subsequent test, they were asked to recognize all the words they had seen previously and give remember, know or guess responses according to whether they recognized words on the basis of autonoetic awareness, noetic awareness, or guessing. Overall, patients showed the same degree of a directed forgetting effect as normal subjects. However, whereas the effect was observed both for remember and know responses in normal subjects, it was observed for know, but not for remember, responses in patients. These results indicate that patients with schizophrenia exhibit an impaired strategic regulation of contents of autonetic awareness for relevant and irrelevant information.

Reduced levels of specific autobiographical memories in schizophrenia.

Autobiographical memory is intrinsically related to the self and personal identity. This study investigated whether both personal episodic memory and semantic memory are impaired in schizophrenia, a disease characterized by an abnormal personal identity. Personal episodic memory and personal semantic memory were investigated in 24 patients with schizophrenia and 24 normal subjects using an autobiographical fluency task and an autobiographical memory inquiry. Autobiographical memory scores and the proportion of specific memories were lower in patients with schizophrenia than in normal subjects. The deficit of personal episodic and semantic memory, as assessed by the autobiographical memory inquiry and the autobiographical fluency task, respectively, was most apparent after the onset of clinical symptoms. Schizophrenia is associated with an impairment of both personal episodic and semantic memory and with a reduction of specific autobiographical memories. Those impairments are consistent with the existence of an abnormal personal identity in patients with schizophrenia.