MRC Cognition and Brain Sciences Unit at University of Cambridge
https://evidence.thinkportal.org/handle/123456789/1613
Postgraduate theses from the Cognition and Brain Sciences Unit2024-03-28T23:17:16ZCharacterising goal neglect by investigating the effects of complexity and task structure
https://evidence.thinkportal.org/handle/123456789/32277
Characterising goal neglect by investigating the effects of complexity and task structure
A fundamental question of human existence is how much control we have on our behaviour. This dissertation aims to add to our understanding of cognitive control by characterising how a particular failure of performance, Goal Neglect (GN), is affected by different forms of complexity manipulations. In Chapter 2, I develop a new task to test GN and unlike previous studies, I manipulate complexity qualitatively by altering the instructional cues - the cues instructing the participant to shift to a different rule set. GN was sensitive to this kind of complexity manipulation and this is linked to a failure in recognizing the significance of the instructional cues. In Chapter 3, I propose a new entropy-like measure to quantify the temporal clustering of GN and use this to test the differential temporal patterns that are predicted by two theoretical models of GN. The results suggest that both models are likely to be operant, but with their relative dominance being different across time: GN early on in the task appears to be mostly driven by failures which are “task model” like, whilst GN which manifests later on is better aligned with the “monitoring” account. Chapter 2 also revealed that GN can be sensitive to manipulations of complexity during task performance, which motivated the question of whether previously published studies suggesting the contrary, were perhaps due to insufficient complexity. Hence, in Chapter 4, using the new GN task, I investigate this further. Overall, the results were mixed and indicated that complexity does not appear to affect GN unless the complexity manipulation is more closely associated to the critical event. Throughout this dissertation, I refer to models and empirical evidence from the Prospective Memory (PM) literature given the apparent similarity between PM and GN experimental paradigms. In Chapter 5, I take this further and investigate how PM failures and GN are different, if at all, with the broader aim to integrate what are otherwise isolated domains. I found a mixture of null findings which suggest that it is not entirely clear if GN and PMf reflect different capacities. Nonetheless, while investigating the differences between GN and PMf, a much more interesting question emerged with respect to what structural features of a task predict different signatures of GN-like and PMf-like errors. The key finding to this theory-neutral approach was a general rule about task structure: a combination of extended practice and low frequency of critical events predict both a larger amount of errors and with more of these occurring late in the task. Overall, this research has shed further light on task conditions that may result in different error signatures and that may reflect different cognitive resources.; The Medical Research Council funded my PhD studies.
Listeners and Readers Generalize Their Experience With Word Meanings Across Modalities
https://evidence.thinkportal.org/handle/123456789/32279
Listeners and Readers Generalize Their Experience With Word Meanings Across Modalities
Research has shown that adults' lexical-semantic representations are surprisingly malleable. For instance, the interpretation of ambiguous words (e.g., bark) is influenced by experience such that recently encountered meanings become more readily available (Rodd et al., 2016, 2013). However, the mechanism underlying this word-meaning priming effect remains unclear, and competing accounts make different predictions about the extent to which information about word meanings that is gained within one modality (e.g., speech) is transferred to the other modality (e.g., reading) to aid comprehension. In two Web-based experiments, ambiguous target words were primed with either written or spoken sentences that biased their interpretation toward a subordinate meaning, or were unprimed. About 20 min after the prime exposure, interpretation of these target words was tested by presenting them in either written or spoken form, using word association (Experiment 1, N = 78) and speeded semantic relatedness decisions (Experiment 2, N = 181). Both experiments replicated the auditory unimodal priming effect shown previously (Rodd et al., 2016, 2013) and revealed significant cross-modal priming: primed meanings were retrieved more frequently and swiftly across all primed conditions compared with the unprimed baseline. Furthermore, there were no reliable differences in priming levels between unimodal and cross-modal prime-test conditions. These results indicate that recent experience with ambiguous word meanings can bias the reader's or listener's later interpretation of these words in a modality-general way. We identify possible loci of this effect within the context of models of long-term priming and ambiguity resolution.
The missing link? Testing a schema account of unitization.
https://evidence.thinkportal.org/handle/123456789/32278
The missing link? Testing a schema account of unitization.
Unitization refers to the creation of a new unit from previously distinct items. The concept of unitization has been used to explain how novel pairings between items can be remembered without requiring recollection, by virtue of new, item-like representations that enable familiarity-based retrieval. We tested an alternative account of unitization – a schema account – which suggests that associations between items can be rapidly assimilated into a schema. We used a common operationalization of “unitization” as the difference between two unrelated words being linked by a definition, relative to two words being linked by a sentence, during an initial study phase. During the following relearning phase, a studied word was re-paired with a new word, either related or unrelated to the original associate from study. In a final test phase, memory for the Relearned associations was tested. We hypothesized that, if unitized representations act like schemas, then we would observe some generalization to related words, such that memory would be better in the definition than sentence condition for related words, but not for unrelated words. Contrary to the schema hypothesis, evidence favoured the null hypothesis of no difference between definition and sentence conditions for related words (Experiment 1), even when each cue was associated with multiple associates, indicating that the associations can be generalized (Experiment 2), or when the schematic information was explicitly re-activated during Relearning (Experiment 3). These results suggest that unitized associations do not generalize to accommodate new information, and therefore provide evidence against the schema account.
Autobiographical episodic memory-based training for the treatment of mood, anxiety and stress-related disorders: A systematic review and meta-analysis.
https://evidence.thinkportal.org/handle/123456789/32275
Autobiographical episodic memory-based training for the treatment of mood, anxiety and stress-related disorders: A systematic review and meta-analysis.
We review evidence for training programmes that manipulate autobiographical processing in order to treat mood, anxiety, and stress-related disorders, using the GRADE criteria to judge evidence quality. We also position the current status of this research within the UK Medical Research Council's (2000, 2008) framework for the development of novel interventions. A literature search according to PRISMA guidelines identified 15 studies that compared an autobiographical episodic memory-based training (AET) programme to a control condition, in samples with a clinician-derived diagnosis. Identified AET programmes included Memory Specificity Training (Raes, Williams, & Hermans, 2009), concreteness training (Watkins, Baeyens, & Read, 2009), Competitive Memory Training (Korrelboom, van der Weele, Gjaltema, & Hoogstraten, 2009), imagery-based training of future autobiographical episodes (Blackwell & Holmes, 2010), and life review/reminiscence therapy (Arean et al., 1993). Cohen's d was calculated for between-group differences in symptom change from pre- to post-intervention and to follow-up. We also completed meta-analyses for programmes evaluated across multiple studies, and for the overall effect of AET as a treatment approach. Results demonstrated promising evidence for AET in the treatment of depression (d=0.32), however effect sizes varied substantially (from -0.18 to 1.91) across the different training protocols. Currently, research on AET for the treatment of anxiety and stress-related disorders is not yet at a stage to draw firm conclusions regarding efficacy as there were only a very small number of studies which met inclusion criteria. AET offers a potential avenue through which low-intensity treatment for affective disturbance might be offered.