Does Stress After Learning Dissociate Memory Systems? Implicit Sequence Learning and Explicit Recognition after the Socially Evaluated Cold-Pressor Test

Stress can modulate the balance between explicit (hippocampal‐dependent) and implicit (striatal‐dependent) memory systems, yet the impact of stress experienced after learning, particularly on implicit memory, remains largely unexplored. We examined whether acute stress administered after incidental...

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Detalles Bibliográficos
Autores: Tamayo, Ricardo M., Rueda-Pérez, Carolina
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/394923
Acceso en línea:http://hdl.handle.net/10261/394923
https://doi.org/10.20350/digitalCSIC/17814
Access Level:acceso abierto
Palabra clave:Stress and memory
Implicit learning
Recognition memory
Serial reaction-time task
Acute stress
Descripción
Sumario:Stress can modulate the balance between explicit (hippocampal‐dependent) and implicit (striatal‐dependent) memory systems, yet the impact of stress experienced after learning, particularly on implicit memory, remains largely unexplored. We examined whether acute stress administered after incidental sequence learning alters subsequent retrieval of implicit and explicit knowledge. Sixty‑seven university students first completed 12 blocks of a serial reaction‑time task (SRTT) embedding a second‑order conditional sequence. Immediately afterward, they underwent either the socially evaluated cold‑pressor test (SECPT; 3 °C, 3 min; n = 34) or a warm‑water control (36 °C; n = 33). During the test phase, participants typed short “old” (trained) and “new” (untrained) subsequences and then judged each fragment as old/new with a 6‑point confidence rating. A 2 (stress) × 2 (sequence type) mixed ANOVA on reaction times (RTs) showed faster responses to old than new fragments (p = .048, η²p = .06), but the stress main effect and the interaction were not significant, indicating a comparable old–new advantage in both groups. Recognition scores likewise revealed a main effect of sequence type (p < .001, η²p = .20), with no stress effect or interaction, confirming that explicit discrimination was equally strong in stressed and control participants. Acute stress applied immediately after learning neither impaired nor enhanced retrieval of procedural nor declarative knowledge. Implicit and explicit measures evolved similarly, consistent with a parallel-or at least non‑competitive- relationship between memory systems under these timing conditions. Our findings establish a baseline for acute stress administered immediately after learning, against which future studies can compare stress applied at other stages: before encoding, during consolidation, or after variable delays preceding retrieval.