Enhance Recall and Recognition memory

Recall or retrieval of memory refers to the subsequent re-accessing of events or information from the past, which have been previously encoded and stored in the brain. In common parlance, it is known as remembering. During recall, the brain "replays" a pattern of neural activity that was originally generated in response to a particular event, echoing the brain's perception of the real event. In fact, there is no real solid distinction between the act of remembering and the act of thinking.

These replays are not quite identical to the original, though - otherwise we would not know the difference between the genuine experience and the memory - but are mixed with an awareness of the current situation. One corollary of this is that memories are not frozen in time, and additional information and suggestions may become incorporated into old memories over time. Thus, remembering can be thought of as an act of creative reimagination.

Because of the way memories are encoded and stored, memory recall is effectively an on-the-fly reconstruction of elements scattered throughout various areas of our brains. Memories are not stored in our brains like books on library shelves, or even as a collection of self-contained recordings or pictures or video clips, but may be better thought of as a kind of collage or a jigsaw puzzle, involving different elements stored in disparate parts of the brain linked together by associations and neural networks. Memory retrieval therefore requires re-visiting the nerve pathways the brain formed when encoding the memory, and the strength of those pathways determines how quickly the memory can be recalled. Recall effectively returns a memory from long-term storage to short-term or working memory, where it can be accessed, in a kind of mirror image of the encoding process. It is then re-stored back in long-term memory, thus re-consolidating and strengthening it.

The efficiency of human memory recall is astounding. Most of what we remember is by direct retrieval, where items of information are linked directly a question or cue, rather than by the kind of sequential scan a computer might use (which would require a systematic search through the entire contents of memory until a match is found). Other memories are retrieved quickly and efficiently by hierarchical inference, where a specific question is linked to a class or subset of information about which certain facts are known. Also, the brain is usually able to determine in advance whether there is any point in searching memory for a fact.

There are two main methods of accessing memory: recognition and recall. Recognition is the association of an event or physical object with one previously experienced or encountered, and involves a process of comparison of information with memory, e.g. recognizing a known face, true/false or multiple-choice questions, etc. Recognition is a largely unconscious process, and the brain even has a dedicated face-recognition area, which passes information directly through the limbic areas to generate a sense of familiarity, before linking up with the cortical path, where data about the person's movements and intentions are processed. Recall involves remembering a fact, event or object that is not currently physically present, and requires the direct uncovering of information from memory, e.g. remembering the name of a recognized person, fill-in the blank questions, etc.

Recognition is usually considered to be “superior” to recall, in that it requires just a single process rather than two processes. Recognition requires only a simple familiarity decision, whereas a full recall of an item from memory requires a two-stage process (indeed, this is often referred to as the two-stage theory of memory) in which the search and retrieval of candidate items from memory is followed by a familiarity decision where the correct information is chosen from the candidates retrieved. Thus, recall involves actively reconstructing the information and requires the activation of all the neurons involved in the memory in question, whereas recognition only requires a relatively simple decision as to whether one thing among others has been encountered before. Sometimes, however, even if a part of an object initially activates only a part of the neural network concerned, recognition may then suffice to activate the entire network.

There are three main types of recall:

• Free recall is the process in which a person is given a list of items to remember and then is asked to recall them in any order (hence the name “free”). This type of recall often displays evidence of either the primacy effect (when the person recalls items presented at the beginning of the list earlier and more often) or the regency effect (when the person recalls items presented at the end of the list earlier and more often), and of the contiguity effect (the marked tendency for items from neighboring positions in the list to be recalled successively).
• Cued recall is the process in which a person is given a list of items to remember and is then tested with the use of cues or guides. When cues are provided to a person, they tend to remember items on the list that they did not originally recall without a cue, and which were thought to be lost to memory. This can also take the form of stimulus-response recall, as when words, pictures and numbers are presented together in a pair, and the resulting associations between the two items cues the recall of the second item in the pair.
• Serial recall refers to our ability to recall items or events in the order in which they occurred, whether chronological events in our autobiographical memories, or the order of the various parts of a sentence (or phonemes in a word) to make sense of them. Serial recall in long-term memory appears to differ from serial recall in short-term memory, in that a sequence in long-term memory is represented in memory as a whole, rather than as a series of discrete items. Testing of serial recall by psychologists have yielded several general rules:
• more recent events are more easily remembered in order (especially with auditory stimuli);
• recall decreases as the length of the list or sequence increases;
• there is a tendency to remember the correct items, but in the wrong order;
• where errors are made, there is a tendency to respond with an item that resembles the original item in some way (e.g. “dog” instead of “fog”, or perhaps an item physically close to the original item);
• repetition errors do occur, but they are relatively rare;
• if an item is recalled earlier in the list than it should be, the missed item tends to be inserted immediately after it;
• if an item from a previous trial is recalled in a current trial, it is likely to be recalled at its position from the original trial.

If we assume that the "purpose" of human memory is to use past events to guide future actions, then keeping a perfect and complete record of every past event is not necessarily a useful or efficient way of achieving this. So, in most people, some specific memories may be given up or converted into general knowledge (i.e. converted from episodic to semantic memories) as part of the ongoing recall/re-consolidation process, so that that we are able to generalize from experience.

It is also possible that false memories (or at least wrongly interpreted memories) may be created during recall, and carried forward thereafter. Research into false memory creation is particularly associated with Elizabeth Loftus' work in the 1970s. Among many other experiments in this area (see the side panel on the Psychogenic Amnesia page, for example), she showed how the precise wording of a question about memories (e.g. "the car hit" or "the car smashed into") can dramatically influence the recall and re-creation of memories, and can even permanently change those memories for future recalls - a phenomenon which is not lost on the legal profession. It is thought that it may even be possible, up to a point, to choose to forget, by blocking out unwanted memories during recall, a process achieved by frontal lobe activity, which inhibits the laying down or re-consolidation of a memory.

Strengthen Recall by Adding These Foods to the Rotation

Eat your veggies. You're not likely to forget this message. Getting adequate vegetables, especially cruciferous ones including broccoli, cabbage and dark leafy greens, may help improve memory. Try a kale salad or substitute collard greens for a tortilla in your next sandwich wrap. Broccoli stir-fry also is an excellent option for lunch or dinner.

Be sweet on berries and cherries. Berries — especially dark ones such as blackberries, blueberries and cherries — are a rich source of anthocyanins and other flavonoids that may boost memory function. Enjoy a handful of berries for a snack, mixed into cereal or baked into an antioxidant-rich dessert. You can reap these benefits from fresh, frozen or dried berries and cherries.

Get adequate omega-3 fatty acids. Essential for good brain health, omega-3 fatty acids, docosahexaenoic acid, or DHA may help improve memory in healthy young adults. Seafood, algae and fatty fish — including salmon, bluefin tuna, sardines and herring — are some of the best sources of omega-3 fatty acids. Substitute fish for meat a couple times each week to get a healthy dose. Grill, bake or broil fish for ultimate flavor and nutrition. Try salmon tacos with red cabbage slaw, snack on sardines or enjoy seared tuna on salad greens for dinner. If you don't eat fish, discuss other food options and supplementation with your doctor or registered dietitian nutritionist. You can get omega-3 fatty acids from fish oil, seaweed or microalgae supplements.

Work in walnuts. Well known for a positive impact on heart health, walnuts also may improve cognitive function. Snack on a handful of walnuts to satisfy midday hunger, add them to oatmeal or a salad for crunch or mix them into a vegetable stir-fry for extra protein.

These foods are not just good for the brain, they sustain a healthy heart and all parts of the body. While there's no guarantee that these foods will help you remember where you put your keys tomorrow, over time they can support lifelong good health.