Different types of working memory binding in epilepsy patients with unilateral anterior temporal lobectomy.
The medial temporal lobe is an important structure for long-term memory formation, but its role in working memory is less clear. Recent studies have shown hippocampal involvement during working memory tasks requiring binding of information. It is yet unclear whether this is limited to tasks containing spatial features. The present study contrasted three binding conditions and one single-item condition in patients with unilateral anterior temporal lobectomy. A group of 43 patients with temporal lobectomy (23 left; 20 right) and 20 matched controls were examined with a working memory task assessing spatial relational binding (object-location), non-spatial relational binding (object-object), conjunctive binding (object-colour) and working memory for single items. We varied the delay period (3 or 6s), as there is evidence showing that delay length may modulate working memory performance. The results indicate that performance was worse for patients than for controls in both relational binding conditions, whereas patients were unimpaired in conjunctive binding. Single-item memory was found to be marginally impaired, due to a deficit on long-delay trials only. In conclusion, working memory binding deficits are found in patients with unilateral anterior temporal lobectomy. The role of the medial temporal lobe in working memory is not limited to tasks containing spatial features. Rather, it seems to be involved in relational binding, but not in conjunctive binding. The medial temporal lobe gets involved when working memory capacity does not suffice, for example when relations have to be maintained or when the delay period is long.
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3 Room B.02.08, 6525 HR Nijmegen, The Netherlands. Electronic address: b.vangeldorp@donders.ru.nl.
Bonnie
B
van Geldorp
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3 Room B.02.08, 6525 HR Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Department of Behavioural Sciences, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: z.bouman@donders.ru.nl.
Zita
Z
Bouman
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3 Room B.02.08, 6525 HR Nijmegen, The Netherlands; Epilepsy Centre Kempenhaeghe, Department of Behavioural Sciences, Postbus 61, 5590 AB Heeze, The Netherlands. Electronic address: m.hendriks@donders.ru.nl.
Marc P H
MP
Hendriks
Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Montessorilaan 3 Room B.02.08, 6525 HR Nijmegen, The Netherlands; Radboud University Nijmegen Medical Centre, Department of Medical Psychology, Postbus 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: r.kessels@donders.ru.nl.
Roy P C
RP
Kessels
D000328:Adult; D038481:Anterior Temporal Lobectomy; D004827:Epilepsy / Q000523:psychology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D013702:Temporal Lobe / Q000503:physiopathology*
Associative memory; Epilepsy surgery; Medial temporal lobe; Working memory