Semantic memory is distinct from episodic memory, which is the memory of experiences and specific events that occur during people's lives, from which they can recreate at any given point. For instance, semantic memory might contain information about what a cat is, whereas episodic memory might contain a specific memory of petting a particular cat. Humans can learn about new concepts by applying their knowledge learned from things in the past. Other examples of semantic memory include types of food, capital cities of a geographic region, facts about people, dates, or the lexicon of a language, such as a person's vocabulary. Hybrid types Autobiographical memory is a memory system consisting of episodes recollected from an individual's life, based on a combination of episodic (personal experiences and specific objects, people and events experienced at particular time and place) and semantic (general knowledge and facts about the world) memory. Spatial memory is the part of memory responsible for recording information about one's environment and its spatial orientation. For example, a person's spatial memory is required in order to navigate around a familiar city, just as a rat's spatial memory is needed to learn the location of food at the end of a maze. It is often argued that in both humans and animals, spatial memories are summarized as a cognitive map. Spatial memory has representations within working, short-term and long-term memory. Research indicates that there are specific areas of the brain associated with spatial memory. Many methods are used for measuring spatial memory in children, adults, and animals. Examples The model of language Declarative and procedural memory fall into two categories of human language. Declarative memory system is used by the lexicon. Declarative memory stores all arbitrary, unique word-specific knowledge, including word meanings, word sounds, and abstract representations such as word category. In other words, declarative memory is where random bits and pieces of knowledge about language that are specific and unpredictable are stored. Declarative memory includes representations of simple words (e.g. cat), bound morphemes (morphemes that have to go together), irregular morphological forms, verb complements, and idioms (or non-compositional semantic units). Irregular morphological structures fall into the declarative system; the irregularities (such as went being the past form of go or idioms) are what we have to memorize. Declarative memory supports a superposition associative memory, which allows for generalizations across representations. For example, the memorization of phonologically similar stem-irregular past tense