A randomized controlled trial of working memory and processing speed training in schizophrenia

Abstract

BackgroundAlthough prior research has shown that cognitive training may improve cognition for schizophrenia patients, it is currently unclear which domains of cognition should be targeted in training. One suggestion is to target low- or mid-level cognitive processes. In particular, working memory (WM) and processing speed (PS) have been named as two key areas of impairment in schizophrenia, and two domains of cognition that are linked to higher-order cognition and daily functioning. This study aimed to investigate the near-transfer (transfer of gains to related contexts), far-transfer (transfer of gains to unrelated contexts), and real-world gains associated with WM and PS training in schizophrenia.MethodsEighty-three participants with schizophrenia were recruited and randomly assigned to computerized WM training, PS training, or a no-training control group. Outcome measures included WM, PS, fluid intelligence, executive functioning, social cognition, and daily functioning and symptoms.ResultsPS training led to significant gains in untrained PS tasks, as well as gains in far-transfer tasks that required speed of processing. WM training did not lead to gains in untrained WM tasks and showed inconsistent effects on some far-transfer tasks.ConclusionsThese results suggest some benefit of domain-specific cognitive training, specifically PS training, in schizophrenia. Far-transfer of gains to other cognitive domains and to real-world functioning may not occur after targeted WM or PS training, though non-specific effects (e.g. through behavioral activation, increased motivation) may lead to improvements in some tasks. Future studies should continue to investigate the mechanisms by which cognitive training may enhance cognition and functioning in schizophrenia.

Advances in Cognitive Remediation Training in Schizophrenia: A Review

“…Out of the 26 studies included, two included a paper-and-pencil format that had dropout rates of 0 [ 9 ] and 8 [ 15 ]. Twenty-three studies included a computerized CRT program with dropout rates ranging from 0 to 53 [ 7 , 8 , 10 , 11 , 12 , 13 , 14 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. One study compared paper-and-pencil and computerized CRT to one another and had 9 total dropouts [ 25 ].…”

“…Both group and individual formats implementing CRT were found from our search. Of the 26 articles, nine studies used an individual format [ 7 , 11 , 12 , 13 , 14 , 23 , 24 , 29 , 31 ] and 17 used a group format [ 8 , 9 , 10 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 25 , 26 , 27 , 28 , 30 , 32 ]. One study [ 22 ] had participants complete homework exercises in their own homes, but the CRT program itself was implemented in a group outpatient setting.…”

Generalized neurocognitive impairment in individuals at ultra‐high risk for psychosis: The possible key role of slowed processing speed

“…Processing speed appears to be particularly important to measure in UHR individuals, also for screening purposes (González‐Blanch et al., 2011), because it may capture the generalized impairment. From a treatment perspective, our study may provide a rationale for targeting this apparently domain‐general neurocognitive mechanism, using behavioral and/or pharmacological interventions to boost neurocognitive processing efficiency (Brébion et al., 2014; Cassetta & Goghari, 2016; Cassetta et al., 2019; Takeuchi & Kawashima, 2012). Thus, a double‐blind randomized clinical trial has shown that UHR individuals receiving processing speed training exhibit improvement not only in processing speed but also in social functioning (Choi et al., 2017).…”

High Schizotypy Predicts Emotion Recognition Independently of Negative Affect

“…As there are currently no investigations in schizotypy or schizophrenia that compares performance to controls on the GERT-S, it cannot be ruled out that our findings are due to the ER instrument used. However, one study has assessed patients using the GERT-S (with no control group) and reported an average score of 53.5% ( 68 ). The average score in this control sample was 62.9% which may suggest the GERT-S is sensitive to detect ER deficits in psychosis patients.…”