Time-based prospective memory is a type of prospective memory in which remembrance is triggered by a time-related cue that indicates that a given action needs to be performed. An example is remembering to watch a television program at 3 p.m.Baddeley, A., & Eysenck, M. (2007). Prospective memory: An overview and synthesis of an emerging field . Sage Publications Ltd. In contrast to time-based prospective memory, event-based prospective memory is triggered by an environmental cue that indicates that an action needs to be performed.McDaniel, M., Einstein, G. (2000). Strategic and automatic processes in prospective memory retrieval: a multiprocess framework. Applied Cognitive Psychology, 14(7), 127-144. An example is remembering to send a letter (the action) after seeing a mailbox (the cue). While event-based memory is dependent on the environment, time-based prospective memory is self-initiated; one must specifically monitor the passage of time.
Neuroanatomy
Rostral prefrontal cortex
Until recently, not a lot has been known about the cognitive functions of the rostral prefrontal cortex, also known as Area 10 of the brain.Burgess, P., Gilbert, S., Dumontheil, I. (2007). Function and localization within rostral prefrontal cortex (area 10). Philosophical Transactions of the Royal Society Biological Sciences, 362, 887-899.Burgess, P., Gilbert, S., Dumontheil, I., Simons, J. (2001). Hypothesis of rostral prefrontal cortex function. Measuring the Mind, 217-248. In humans, this area of the brain is very large (25-30 cubic cm). The Rostral Prefrontal Cortex supports a cognitive system that reflects either stimulus-oriented (SO) or stimulus-independent (SI) attending. SI attending supports self-generated or self-maintained thought, which is important in prospective memory. This part of the brain has also been shown to play a crucial role in the maintenance and realization of delayed intentions.Okuda, J.T. (2007). Differential involvement of regions of rostral prefrontal cortex (Brodmann area 10) in time- and event-based prospective memory. International Journal of Psychophysiology, 64(3), 233-246. Delayed intentions triggered by event cues are well understood; time cues however have been less studied.
In a positron emission tomography (PET) study, participants were asked to make a prospective response in either an event-based or time-based task condition. Differences in activation of regions of the rostral prefrontal cortex were seen in the results according to whether the task was time- or event- based. Three rostral prefrontal regions were more active in the time-based condition: the right superior frontal gyrus, anterior medial frontal lobe and anterior cingulate gyrus. These results suggest that there are different processing demands made by event- or time- based prospective memory tasks.Burgess, P., Frith, C., Scott, S. (2003) The role of the rostral cortex (area 10) in prospective memory: a lateral versus medial dissociation. Neuropsychologia, 41. 906-918.
Parietal lobe
In terms of prospective memory, the parietal lobe plays an important role in processing and recognizing cues that trigger and keep attention focused on intended actions while performing other tasks. This part of the brain is activated most intensely when these cues are visual or spatial.Burgess, P.W., Quayle, A., & Frith, C.D. (2001). Brain regions involved in prospective memory as determined by positron emission tomography. Neuropsychologia, 39, 545–555. The parietal lobe is located in the superior region of the brain above the occipital lobe and behind the frontal lobe.Martin, T., McDaniel, M.A., Guynn, M.J., Houck, J.M., Woodruff, C.C., Bish, J.P., et al. (2007). Brain regions and their dynamics in prospective memory retrieval: A MEG study. International Journal of Psychophysiology, 64, 247–258.
For time-based prospective memory, the parietal lobe is important especially when an individual is required to remember numbers, more specifically, a certain time that will act a cue to perform an intended task.Pardo, J.V., Fox, P.T, & Raichle, M.E. (1991). Localization of a human system for sustained attention by positron emission tomography. Nature, 349, 61-65. The activation of this area is studied using PET as well as magnetoencephalography (MEG). Damage to this area of the brain increases the difficulty of performing time-based tasks more significantly than it does event-based tasks.Evans, J., Groot, Y., Watson, P., Wilson, B. (2002). Prospective memory functioning in people with and without brain injury. Journal of the International Neuropsychological Society, 8. 645-654. This is because time-based tasks place more demand on inhibitory control mechanisms than do event-based tasks.
Factors affecting prospective memory
Age
Age is a significant factor that affects prospective memory. Smith et al. (2010) conducted a study comparing time-based prospective memory in children and young adults; they found an increase in preparatory attentional processing for adults –suggesting an improvement of time-based prospective memory from childhood to young adulthood.Smith, R.E., Bayen, U., Martin, C. (2010). The cognitive processes underlying event-based prospective memory in school-age children and young adults: A formal model-based study. Developmental Psychology, 46(1), 230-244. Consistent with the results of the prior study, Ceci and Bronfenbrenner (1985) found that in a time-based task with 10-year-olds and 14-year-olds, time monitoring was greater among older children.Ceci, S.J., Bronfenbrenner U. (1985). “Don't forget to take the cupcakes out of the oven”: Prospective memory, strategic time-monitoring, and context. Child Development, 56(1), 152–164.
Another study by Kvavilashvili et al. (2009) comparing time-based prospective memory among young adults (18- to 30-year-olds), young-old adults (60- to 75-year-olds) and old-old adults (79- to 90-year-olds), found that young adults performed the best on time-based tasks.Kvavilashvili, L., Kornbrot, D. E., Mash, V. (2009) Differential effects of age on prospective and retrospective memory tasks in young, young-old, and old-old adults. Memory, 17(2), 180-196. A study further compared the difference between young-old adults and old-old adults in time-based prospective memory, finding that young-old adults outperformed old-old adults.Schnitzspahn, K. M., Kliegel, M. (2009) Age effects in prospective memory performance within older adults: the paradoxical impact of implementation intentions. European Journal of Ageing, 6, 147-155. The findings of the above studies suggest that there is ongoing improvement of time-based prospective memory from childhood into young adulthood; however, a decrease begins in later adulthood.
Substance use
Substance abuse refers to the harmful use of substances, including alcohol and illicit drugs. Multiple studies have shown that abuse of substances can damage our memory system. Current research has looked at the effect of substances on prospective memory; ability to remember to do something in the future. In particular it has been found that cannabis, ecstasy, methamphetamine and alcohol are substances that directly affect time-based prospective memory.
Cannabis
Marijuana is the world's most commonly abused illicit drug. The effects of cannabis are associated with deficits in memory, learning, decision-making, and speed of processing.Bartholomew, J., Holroyd, S., Heffernan, T. (2010). Does cannabis use affect prospective memory in young adults? Journal of Psychopharmacology, 24(2), 241-246. Montgomery et al. (2012) conducted a study on twenty cannabis-only users and 20 non-illicit drug users to test the effect of cannabis on prospective memory.Montgomery C., Seddon, A., Fisk, E., Murphy, P., Jansari, A. (2012). Cannabis-related deficits in real-world memory. Human Psychopharmacology: Clinical and Experimental, 27(2), 217–225. Cannabis users found it more difficult to perform an action at a certain time than nonusers. The results provide support for the cannabis-related deficits in prospective memory.
Ecstasy
Prospective memory impairments in recreational drug users have been documented in recent years.Hadjiefthyvoulou, F., Fisk, J., Montgomery, C., Bridges, N. (2011). Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge prospective memory test. Psychopharmacology, 215(4), 761–774. Hadjiefthyvoulou et al. (2011) compared performance of ecstasy users, cannabis users, and nonuser on both event and time-based prospective memory tasks. Ecstasy users performed significantly worse in comparison to both cannabis only and non-user groups on time-based tasks. Time-based prospective memory is sensitive to regular and even moderate use of ecstasy.Rendell, P. G., Gray, T. J., Henry, J. D., Tolan, A. (2007). Prospective memory impairment in “ecstasy” (MDMA) users. Psychopharmacology, 194, 497-504. More importantly, ecstasy users experience generalized difficulties with prospective memory, demonstrating that these deficits are likely to have important implications for daily functioning.
Methamphetamine
Methamphetamine more commonly known as crystal meth, is a highly addictive drug. A fair amount of research indicates that the use of methamphetamine is associated with neurocognitive impairment, more recently there has been a focus on whether these difficulties extend to memory for future intentions.Rendell, P. G., Mazur, M., Henry, J. D. (2009). Prospective memory impairment in former users of methamphetamine. Psychopharmacology, 203, 609-616. Rendell et al. (2009) found that impairments in time-based prospective memory existed in both current and former users of methamphetamine.
Alcohol
Research has shown that heavy alcohol use clearly leads to deficits in memory. Less is known about the effects of alcohol on day-to-day memory function, specifically, prospective memory, remembering to do things at some future point in time.Heffernan, T., Moss, M., Ling, J. (2001). Subjective ratings of prospective memory deficits in chronic heavy alcohol users. Alcohol and Alcoholism, 37(3), 269-271. The results of a study conducted by Heffernan et al. (2010) suggest that binge drinking in the teenage years leads to impairments in everyday prospective memory.Heffernan, T., Clark, R., Bartholomew, J., Ling, J., Stephens, S. (2010). Does binge drinking in teenagers affect their everyday prospective memory? Drug and Alcohol Dependence, 109, 72-78. A study by Heffernan and O'Neill (2011) further investigated the effect has alcohol on time-based prospective memory and concluded that binge drinking was associated with significantly reduced performance on time-based tasks.Heffernan, T., O'Neill, T. (2011). Time based prospective memory deficits associated with binge drinking: evidence from the Cambridge prospective memory test. Drug and Alcohol Dependence
Disease and disorders
There has been an increase in interest of studying prospective memory deficiencies in individuals with disease or disorder; because daily life largely relies on previously planned intentions a lack thereof would cause major issues for an affected individual. It has been found that many diseases and disorders have negative impacts on prospective memory; the effects extend from mild cognitive impairment to dementia.Edgecombe, M.S., Woo, E., Greeley, D.R. (2009). Characterizing multiple memory deficits and their relation to everyday functioning in individuals with mild cognitive impairment. Neuropsychology, 23(2), 168-177.Thompson, C., Henry, J. D., Rendell, P. G., Withall, A., Brodaty, H. (2010). Prospective memory function in mild cognitive impairment and early dementia. Journal of the International Neuropsychological Society, 16, 318-325.
Parkinson's disease