The Influence Of Intervening Activities And Testing Conditions On The Accuracy And Confidence Of Source Memory

The research in this thesis investigated factors that influence a particular type of source memory decision, the discrimination between memories that originate with others and memories that originate with ourselves. In their reality monitoring model, Johnson & Raye (1981) characterize the source decision process as an attribution based on an examination of memory rather than the retrieval of a label or tag that specifies a memory\u27s source. Their research demonstrated that subjects rely on information from initial encoding to guide their decisions about the origins of their memories. The present research examined the influence of events occurring after encoding on source memory decisions. Postevent information (e.g., Loftus, 1991b) and the manner in which information is later processed (e.g., Jacoby, Kelley, & Dywan, 1989) are known to influence other types of memory judgments. More specifically, the purpose of the present research was to investigate the influence of events that occur after initial encoding, either during the period between study and test or at the time of testing, on the accuracy of source judgments and the confidence subjects express for those judgments. An additional focus of interest was the relationship between confidence in a memory and source decision accuracy.;The results of the present experiments indicated that source attribution errors were likely to occur when information was processed again in a manner that differed from that at original encoding. Source decision errors increased when the conflicting presentations were part of the actual memory test (Experiments 1, 2, & 3) as well as when they occurred between study and test (Experiment 4). The confidence exhibited in source attributions was not always a reliable indicator of decision accuracy (Experiments 2 & 3) and under certain testing conditions subjects displayed inappropriate confidence for some of their erroneous source judgments. Finally, although ratings of memory strength (as indicated by confidence in recognition) generally predicted word recognition performance, strong memories were not necessarily associated with accurate source attributions (Experiments 3 & 4).;Overall, the results of the present studies are consistent with the reality monitoring model (Johnson & Raye, 1981) and the more encompassing source monitoring framework (Johnson, Hashtroudi, & Lindsay, 1993). Considered together, the results of the present studies extend the previous work by demonstrating that events occurring after a memory has been formed may influence decisions about how that memory was acquired

Performing E-mail Tasks While Driving: The Impact of Speech-Based Tasks on Visual Detection

Drivers listened and responded to e-mail messages presented in ahuman voice and two types of synthetic speech (concatenative and formant) whiledriving a simulator. Their performance for visual event detection, vehicle control,and message responses was assessed. Results indicated that the type of speechoutput system affected drivers’ detection of visual changes in the drivingenvironment; they were poorer at detecting these events when either of thesynthetic speech systems was used. Drivers detected fewer visual changes duringthe difficult messages than during the baseline driving. No effects of the speechsystem type or e-mail message difficulty were observed on the vehicle controlmeasures. Drivers were also less accurate when responding to message content formessages presented in synthetic speech (concatenative) compared with recordedhuman voice. Subjective ratings indicated that listening to the synthetic speechrequired more mental effort than listening to the recorded human voice.Preference ratings for the interfaces decreased as mental effort increased. Theresults indicated that although drivers were not required to direct their attentionaway from the road, using the speech-based interfaces reduced drivers’ visualevent detection and their response accuracy to messages themselves

Three Navigation Systems With Three Tasks: Using the Lane-Change Test (LCT) to Assess Distraction Demand

The Lane Change Test (ISO, 2008; Mattes, 2003) was used to assess distraction demand when drivers completed three typical navigation tasks (an easy navigation task, a point of interest task and a difficult navigation task) using three different navigation systems. In order for the LCT to be a useful procedure, it must distinguish good from poor navigation systems and acceptable from unacceptable tasks performed using those systems. The results provide some general support for the LCT as a sensitive measure of distraction. Some aspects of the results, however, called into question the adequacy of the LCT as a sufficient measure of distraction. In particular, the LCT was found to be insensitive to task demands arising from excessive task duration. Since risk exposure is a function of secondary task duration (as well as other factors such as intensity, frequency and timing), it is recommended that a measure of task duration be incorporated in the LCT procedure. When the MDEV was modified to incorporate task duration, the resulting measure (mean deviation per average task) reflected more adequately the interaction demands of the various navigation tasks

Glance behaviours when using an in-vehicle smart driving aid : a real-world, on-road driving study

In-vehicle information systems (IVIS) are commonplace in modern vehicles, from the initial satellite navigation and in-car infotainment systems, to the more recent driving related Smartphone applications. Investigating how drivers interact with such systems when driving is key to understanding what factors need to be considered in order to minimise distraction and workload issues while maintaining the benefits they provide. This study investigates the glance behaviours of drivers, assessed from video data, when using a smart driving Smartphone application (providing both eco-driving and safety feedback in real-time) in an on-road study over an extended period of time. Findings presented in this paper show that using the in-vehicle smart driving aid during real-world driving resulted in the drivers spending an average of 4.3% of their time looking at the system, at an average of 0.43 s per glance, with no glances of greater than 2 s, and accounting for 11.3% of the total glances made. This allocation of visual resource could be considered to be taken from ‘spare’ glances, defined by this study as to the road, but off-centre. Importantly glances to the mirrors, driving equipment and to the centre of the road did not reduce with the introduction of the IVIS in comparison to a control condition. In conclusion an ergonomically designed in-vehicle smart driving system providing feedback to the driver via an integrated and adaptive interface does not lead to visual distraction, with the task being integrated into normal driving

Using the Lane-Change Test (LCT) to Assess Distraction: Tests of Visual-Manual and Speech-Based Operation of Navigation System Interfaces

The Lane Change Test (LCT) is an easy-to-implement, low-cost methodology for the evaluation of the distraction associated with performing invehicle tasks while driving (Mattes, 2003). In the present study, the LCT was used to assess driving performance when drivers completed navigation tasks using visual-manual or speech-based interfaces. Drivers performed two types of navigation tasks at two levels of difficulty. The results provide support for the LCT as an effective measure of distraction for both types of interface. It is recommended that the LCT procedure incorporate additional measures beyond the current mean deviation measure. Two measures are suggested: Lane Change Initiation, which reflects the aspects of driving having to do with detection and response delay as a result of distraction, and a measure of task duration to account for risk exposure

Detection Response Tasks: Using Remote, Headmounted and Tactile Signals to Assess Cognitive Demand While Driving

Three versions of the Detection Response Task (DRT) were evaluated and compared as methods to assess cognitive demand while driving. Participants performed tasks known to manipulate cognitive demand (N_Back tasks) and realworld cognitive demand tasks using the iPhone interface, Siri, while driving a simulator. The Remote DRT, the Head Mounted DRT and the Tactile DRT were all sensitive to task demands but advantages were found to using the newer versions for the assessment of cognitive distraction. This work is part of an international collaborative research effort to standardize the DRT (ISO WD17488)

Is it reliable to assess visual attention of drivers affected by Parkinson's disease from the backseat?—a simulator study

BACKGROUND: Current methods of determining licence retainment or cancellation is through on-road driving tests. Previous research has shown that occupational therapists frequently assess drivers' visual attention while sitting in the back seat on the opposite side of the driver. Since the eyes of the driver are not always visible, assessment by eye contact becomes problematic. Such procedural drawbacks may challenge validity and reliability of the visual attention assessments. In terms of correctly classified attention, the aim of the study was to establish the accuracy and the inter-rater reliability of driving assessments of visual attention from the back seat. Furthermore, by establishing eye contact between the assessor and the driver through an additional mirror on the wind screen, the present study aimed to establish how much such an intervention would enhance the accuracy of the visual attention assessment. METHODS: Two drivers with Parkinson's disease (PD) and six control drivers drove a fixed route in a driving simulator while wearing a head mounted eye tracker. The eye tracker data showed where the foveal visual attention actually was directed. These data were time stamped and compared with the simultaneous manual scoring of the visual attention of the drivers. In four of the drivers, one with Parkinson's disease, a mirror on the windscreen was set up to arrange for eye contact between the driver and the assessor. Inter-rater reliability was performed with one of the Parkinson drivers driving, but without the mirror. RESULTS: Without mirror, the overall accuracy was 56% when assessing the three control drivers and with mirror 83%. However, for the PD driver without mirror the accuracy was 94%, whereas for the PD driver with a mirror the accuracy was 90%. With respect to the inter-rater reliability, a 73% agreement was found. CONCLUSION: If the final outcome of a driving assessment is dependent on the subcategory of a protocol assessing visual attention, we suggest the use of an additional mirror to establish eye contact between the assessor and the driver. The clinicians' observations on-road should not be a standalone assessment in driving assessments. Instead, eye trackers should be employed for further analyses and correlation in cases where there is doubt about a driver's attention

Pedestrian Injury and Human Behaviour: Observing Road-Rule Violations at High-Incident Intersections

Background Human behaviour is an obvious, yet under-studied factor in pedestrian injury. Behavioural interventions that address rule violations by pedestrians and motorists could potentially reduce the frequency of pedestrian injury. In this study, a method was developed to examine road-rule non-compliance by pedestrians and motorists. The purpose of the study was to examine the potential association between violations made by pedestrians and motorists at signalized intersections, and collisions between pedestrians and motor-vehicles. The underlying hypothesis is that high-incident pedestrian intersections are likely to vary with respect to their aetiology, and thus are likely to require individualized interventions – based on the type and rate of pedestrian and motorist violation. Methods High-incident pedestrian injury intersections in Vancouver, Canada were identified using geographic information systems. Road-rule violations by pedestrians and motorists were documented at each incident hotspot by a team of observers at several different time periods during the day. Results Approximately 9,000 pedestrians and 18,000 vehicles were observed in total. In total for all observed intersections, over 2000 (21%) pedestrians committed one of the observed pedestrian road-crossing violations, while approximately 1000 (5.9%) drivers committed one of the observed motorist violations. Great variability in road-rule violations was observed between intersections, and also within intersections at different observation periods. Conclusions Both motorists and pedestrians were frequently observed committing road-rule violations at signalized intersections, suggesting a potential human behavioural contribution to pedestrian injury at the study sites. These results suggest that each intersection may have unique mechanisms that contribute to pedestrian injury, and may require targeted behavioural interventions. The method described in this study provides the basis for understanding the relationship between violations and pedestrian injury risk at urban intersections. Findings could be applied to targeted prevention campaigns designed to reduce the number of pedestrian injuries at signalized intersections