The role of prior familiarisation and meaningfulness of verbal and visual stimuli on directed forgetting.

ABSTRACTIntentional forgetting of unwanted information is a crucial cognitive function that is often studied with directed forgetting (DF) procedure, whereby cuing some study materials with Forget (F) instruction impairs their memory compared to cuing with Remember (R) instruction. This study investigates how the nature of information (verbal or pictorial), its semantic significance (meaningful or meaningless), and the degree of prior episodic familiarity influence DF. Before the DF phase, stimuli were familiarised by pre-exposing them 0, 2, or 6 times in a prior preview phase. Finally, memory for all items was assessed with old/new recognition test. Experiment 1 employed words, Experiment 2 utilised fractal images, Experiment 3 featured both meaningful and meaningless object images, and Experiment 4 used words and nonwords. Our results indicate that materials that produced better memory performance are not always harder to intentionally forget. Previewed items showed reduced DF compared to non-previewed items regardless of the nature of information, and meaningless stimuli are challenging to intentionally forget regardless of their degrees of familiarisation unless they are meaningless verbal materials. Collectively, the results highlight the importance of joint consideration of the stimulus format, its meaningfulness, and its episodic familiarity in understanding conditions that interact with intentional forgetting.

Trial-level fluctuations in pupil dilation at encoding reflect strength of relational binding.

Eye-tracking methodologies have revealed that eye movements and pupil dilations are influenced by our previous experiences. Dynamic fluctuations in pupil size during learning reflect in part the formation of memories for learned information, while viewing behavior during memory testing is influenced by memory retrieval and drawn to previously learned associations. However, no study to date has linked fluctuations in pupil dilation at encoding to the magnitude of viewing behavior at test. The current investigation involved monitoring eye movements both in single item recognition and relational recognition tasks. In the item task, all faces were presented with the same background scene and memory for faces was subsequently tested, whereas in the relational task each face was presented with its own unique background scene and memory for the face-scene association was subsequently tested. Pupil size changes during encoding predicted the magnitude of preferential viewing during test, as well as future recognition accuracy. These effects emerged only in the relational task, but not in the item task, and were replicated in an additional experiment in which stimulus luminance was more tightly controlled. A follow-up experiment and additional analyses ruled out differences in orienting instructions or number of fixations to the encoding display as explanations of the observed effects. The results shed light on the links between pupil dilation, memory encoding, and eye movement patterns during recognition and suggest that trial-level fluctuations in pupil dilation during encoding reflect relational binding of items to their context rather than general memory formation or strength. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Can intentional forgetting reduce the cross-race effect in memory?

Across three studies, we utilized an item-method directed forgetting (DF) procedure with faces of different races to investigate the magnitude of intentional forgetting of own-race versus other-race faces. All three experiments shared the same procedure but differed in the number of faces presented. Participants were presented with own-race and other-race faces, each followed by a remember or forget memory instruction, and subsequently received a recognition test for all studied faces. We obtained a robust cross-race effect (CRE) but did not find a DF effect in Experiment 1. Experiments 2 and 3 used shorter study and test lists and obtained a significant DF effect along with significant CRE, but no interaction between face type and memory instruction. The results suggest that own-race and other-race faces are equally susceptible to DF. The results are discussed in terms of the theoretical explanations for CRE and their implications for DF.

Directed forgetting in associative memory: Dissociating item and associative impairment.

We report three item-method directed forgetting (DF) studies to evaluate whether DF impairs primarily item memory, or whether it also impairs associative memory. The current studies used a modified associative recognition paradigm that allowed disentangling item impairment from associative impairment in DF. Participants studied scene-object pairings, followed by DF cues (item-method), and at test were presented with a previously studied scene along with three objects, one of which was studied with that scene (target), whereas the remaining two objects were studied with different scenes (lures). Experiment 1 used an associative encoding orienting task, and DF impairment was observed only when the forget targets were paired with forget lures within the test display; however, DF was eliminated when the forget targets were paired with remember lures, possibly due to a recall-to-reject strategy. Experiment 2 used an object-focused orienting task that downplayed the encoding of associative information. The results revealed the opposite of Experiment 1, with significant DF when the forget targets were paired with remember lures, and no DF when the lures and the target came from the same memory instruction. Experiment 3 used the same orienting task as Experiment 1, but testing used a sequential procedure, where item recognition was assessed first, followed by associative recognition test. Conditionalizing associative recognition on item recognition outcomes confirmed that DF impairment of associative memory can be obtained despite retained memory for forget-cued objects. Overall, the results provide strong support for the impairment of associative memory by DF. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Eye movement analyses of strong and weak memories and goal-driven forgetting.

Research indicates that eye movements can reveal expressions of memory for previously studied relationships. Specifically, eye movements are disproportionately drawn to test items that were originally studied with the test scene, compared to other equally familiar items in the test display - an effect known as preferential viewing (e.g., Hannula, Ryan, Tranel, & Cohen, 2007). Across four studies we assessed how strength-based differences in memory are reflected in preferential viewing. Participants studied objects superimposed on background scenes and were tested with three-object displays superimposed on the scenes viewed previously. Eye movements were monitored at test. In Experiment 1 we employed an item-method directed forgetting (DF) procedure to manipulate memory strength. In Experiment 2, viewing patterns were examined across differences in memory strength assessed through subjective confidence ratings. In Experiment 3, we used spaced repetitions to objectively strengthen items, and Experiment 4 involved a list-method DF manipulation. Across all experiments, eye movements consistently differentiated the effect of DF from other strength-based differences in memory, producing different viewing patterns. They also differentiated between incidental and successful intentional forgetting. Finally, despite a null effect in recognition accuracy in list-method DF, viewing patterns revealed both common as well as critical differences between list-method DF and item-method DF. We discuss the eye movement findings from the perspective of theoretical accounts of DF and other strength-based differences in memory.